The present investigation was supported by the Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic (project 2/0112/22).&#160;The present investigation was also supported by ERA-MIN3 POTASSIAL 27 project.

1. Preparation of CuS mixture with the stoichiometry 1.6:1
<ol>
	<li>Tare the weighing paper.</li>
	<li>Weigh 7.6024 g of elemental copper and 2.3974 g of elemental sulfur powder to achieve the stoichiometry ratio of Cu and S at 1.6:1, with a total mass of 10 g.</li>
	<li>Before milling, mix the Cu and S powder. After weighing, introduce both Cu and S powders into a plastic weighing dish and mix intensively with a spatula, until a powder of homogeneous color free from large lumps of sulfur is obtained. 
	NOTE: The purpose of the mixing is to homogenize the powder and ensure a uniform distribution of powders before the milling experiment.</li>
</ol>
2. Preparation of SnSe mixture with the stoichiometry 1:1
<ol>
	<li>Tare the weighing paper.</li>
	<li>Weigh 6.0055 g of Sn and 3.9945 g of Se to make the stoichiometry ratio 1:1, with a total mass of 10 g.</li>
	<li>Before milling, mix the Sn and Se powder by using a spatula to ensure homogeneity (the rules from 1.3 also apply here).</li>
</ol>
3. Sensor setup
<ol>
	<li>Place the sensor board on the top of the jar lid and insert the sensor transistor into the small hole that passes through the lid.</li>
	<li>Switch on the sensor device and connect it to the software on the laptop via Bluetooth.</li>
</ol>
4. Performing milling with in situ temperature monitoring
NOTE: The necessary equipment, including the scheme of the temperature monitoring device, is shown in Figure 1.
<ol>
	<li>Insert tungsten carbide balls, as specified in Table 1, into the milling jar using the tweezers or just &#34;pour&#34; them inside using gravitational force.</li>
	<li>Transfer the prepared sample either from section 1 or section 2 to the tungsten carbide milling jar for the synthesis of Cu1.8S or SnSe.</li>
	<li>Close the milling jar with the lid that has been set up with the sensor from section 3.</li>
	<li>Load the jar into the mill by placing the jar and the counterweight into the P7 planetary mill and setting the parameters on the display as specified in Table 1.</li>
	<li>Type the name of the sample on the active software.</li>
	<li>Press the Start button on the milling display.</li>
	<li>After hearing the milling start, click Start in the active software for the sensor to begin recording the temperature during milling.</li>
	<li>When the MSR occurs, indicated by the sudden increase in temperature, stop the milling and the temperature measurement immediately. 
	NOTE: Repeat the experiment with the same system once again for reproducibility</li>
</ol>
5. Collecting samples
<ol>
	<li>Open the jar over a paper sheet in the fume hood, separate the milling balls by sieving the powder through the strainer. The balls remain on the strainer while the fine powder drops on the paper. In the case of large agglomerates, these are removed from ther strainer using tweezers.&#160;Collect the sample from the paper.</li>
</ol>
6. Transferring the powders
<ol>
	<li>Transfer the powders from the paper to the glass vials using the gravitational force and&#160;spatula, label them, and store them in the desiccator before the measurement.</li>
</ol>
7. Labeling the glass vials
<ol>
	<li>Label the glass vials based on the sample name.</li>
</ol>
8. Cleaning the jar and sensor
<ol>
	<li>Clean the sensor transistor by wiping it with the tissue soaked in etaben.</li>
	<li>In the case of the jar, pour 75 mL of the etaben solution into the milling jars and perform milling at 300 rpm for 5 min.</li>
	<li>Use a steel strainer to collect the balls from the jars, and dispose of the toxic aqueous waste into the container.</li>
	<li>Repeat steps 8.2 and 8.3 until the jar and the balls are free from the solid powder.</li>
</ol>
9. Processing data from in situ temperature monitoring
<ol>
	<li>After finishing the monitoring, the software saves the data automatically as .xlsx files in the download folder on the computer.</li>
	<li>Process the data in the data treatment software to plot the graph temperature vs time. The raw data obtained from the measurement are directly stored as a .csv file and are already segregated into columns.</li>
</ol>
10. Powder X-ray diffraction (XRD) measurement
<ol>
	<li>Crush the obtained samples by using a mortar and pestle. The samples&#39; appearance is depicted in Figure 2.</li>
	<li>Transfer each sample with a spatula to the sample holders and label each sample holder.</li>
	<li>Gently compress the powder with a glass slide, carefully sliding or rotating it to flatten the surface evenly.</li>
	<li>Transfer the sample holder to the XRD diffractometer.</li>
	<li>Set up the XRD measurement in the computer using the XRD commander program programming the given measurement conditions. 
	NOTE: The instrument used in this study is an X-ray diffractometer using CuK&#945; (40 kV, 40 mA) radiation. The parameter for the powder X-ray diffraction (PXRD) experiment: 2-theta range: 10&#176;-80&#176;, step time: 1 s, step size 0.05 s.</li>
	<li>Start the PXRD measurement. The XRD data is saved as a &#34;.raw file &#34;on the computer disk.</li>
	<li>After finishing the measurement, collect the powder back from the sample holder into the glass vial using paper.</li>
	<li>Convert the .raw file into another file type that is suitable for processing in data treatment software (e.g., Origin) 
	NOTE: The PowDLL converter will allow one to convert the file extensions to the desired extension, for example, to .xy format, which is required for Rietveld refinement.</li>
</ol>
11. Rietveld refinement
<ol>
	<li>Do the proper semi-quantitative phase analysis using the XRD software to identify the phases that will be included in the refinement.</li>
	<li>Download corresponding .CIF files from the internet, e.g., from Crystallography Open Database. Download the one for CuS, rhombohedral Cu1.8S, cubic Cu1.8S, SnSe, and SnSe2.</li>
	<li>Run JEdit and powder diffraction data analysis software. 
	NOTE: The powder diffraction data analysis software used here is Topas Academic software. JEdit was formerly modified to be capable of working with the powder diffraction data analysis software.</li>
	<li>Create an input file in JEdit. Ensure that the file contains information about the diffractometer and structural parameters of the phases that are included in the refinement.</li>
	<li>Decide which parameters will be refined.</li>
	<li>Run the refinement in powder diffraction data analysis software. The software saves the result in the .out file, which automatically becomes the new input &#34;.inp&#34; file if another refinement is run.</li>
	<li>Modify the input parameters to get the best refinement possible (determined by the Rwp factor) and run the refinement again.</li>
	<li>Once it is not possible to further improve the refinement, modify the input file in such a way as to save also the results as a .xyd file, which can be read by Origin software.</li>
	<li>Run the refinement for one last time and export the .xyd file.</li>
	<li>Find the information about crystallite size and phase composition in the refinement result (there is an option to run the refinement to provide this information) and note it down.</li>
	<li>Process the data in data analysis software and make the final figures. 
	NOTE: This study used Origin software.</li>
</ol>

Synthesis of High-ZT Thermoelectric Materials via Mechanochemical Methods

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X., Feng, J., Ge, Z. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Enhanced+thermoelectric+performance+of+Cu1.8S+via+lattice+softening.">Enhanced thermoelectric performance of Cu1.8S via lattice softening.</a> Chem. Eng. J. 428, 131153 (2022).</li><li>Zhao, L. 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The authors have no competing financial interests

Mechanically induced self-propagating reactions (MSR) are an immediate transformation of precursors into products via an exothermic combustion-like process activated by mechanical action (similar to self-heat sustaining reactions where similar processes are activated by heat). The occurrence of MSR can often be identified by changes in the physical appearance of the product, a distinct smell at the moment of the reaction, or a scratching sound from the milling&#160;jar. However, empirical evidence suggests that these sensory indicators are not always reliable, and in many cases, the MSR event may not have occurred despite the presence of these signs16.
Gas temperature&#160;and pressure sensors have been developed and mounted into milling jar lids in the past&#160;to address these limitations, and numerous studies on the MSR events in chemical synthesis have been reported20,21,22. However, the valuable equipment is expensive and not interchangeable between jars. Therefore, we developed an economical temperature sensor for observing MSR during planetary&#160;ball milling. This sensor provides a cost-effective and practical alternative to a more expensive and less sensitive sensor system since, in the present case, the sensor is directly in contact with the gas and sometimes also powder. The sensor, placed inside a small hole in the jar&#39;s lid close to the powder and milling balls, transfers the heat generated inside the jar into a readable temperature measurement. This principle allows for real-time monitoring of the MSR through the conversion of heat into an electrical signal, enabling precise and continuous temperature tracking. The fastest scan rate of the temperature is 80 ms. The sensor demonstrated high sensitivity to local temperature changes inside the jar, as evidenced by the real-time monitoring of temperature fluctuations during steps 4.7 and 4.8 in the protocol.
The MSR occurred much faster in the Cu-S system than in the case of Sn-Se. This is in agreement with our previous works14,19. The difference between the repeated experiments in the case of ignition time is not large and is within an experimental error. Notably, the transformation to the SnSe phase was rapid, occurring within the range between 87 and 97 seconds for all three experiments, respectively. In the case of Cu1.8S synthesis, the MSR event was observed consistently in all four trials, always within the first second of milling. However, there were big differences in terms of the temperature increase in both systems. This is most probably related to the fact that the hot particles will get close to the sensor or not, which might always be different. Thus, the temperature increase cannot be considered as a relevant parameter, at least with the current setup. Nevertheless, it seems that the temperature increase is milder in the Cu-S system. The obtained products exhibit distinct physical characteristics compared to the precursors. Cu1.8S, appearing blue and agglomerated (Figure 2A,B), suggests the occurrence of the MSR. The dark blue color is typical for covellite, CuS and the photograph was taken for the sample Cu1.8S-1 where, according to XRD, the content of covellite was around 10 %. For the samples where the amount of covellite was lower, the color of the product was black,e.g., Cu1.8S-4. The SnSe products were always gray.
The X-ray diffraction, in combination with proper data treatment, is an extremely powerful tool to describe the phase composition of the products. Copper sulfides produced via the mechanochemical synthesis can possess different phase compositions, depending on the precursors used. For example in Godo&#269;&#237;kov&#225; et al.23, when the copper acetate (CH3COO)2Cu.4H2O and Na2S were milled, covellite and chalchantite (CuSO4.5H2O) were obtained. When the synthesis was performed on a larger scale in an eccentric vibratory mill, utilizing the Cu:S stoichiometric ratio 1:1 yielded the formation of CuS and Cu2S phases24. Our group was the first to report the MSR event for Cu-S system16, and it was found that CuS and Cu1.8S are formed as a result of MSR when treating 1:1 stoichiometry, with covellite becoming more pronounced with prolonged milling25. It has to be noted that copper has to have a specific needle-like morphology to react via a&#160;MSR14,16. As mentioned in the results part, there are differences in the phase composition of the XRD patterns of Cu1.8S samples. These differences are most probably caused by the time how fast we were able to stop the milling process after the MSR event. According to Bal&#225;&#382; et al.3, almost pure digenite is formed after MSR, which is in accordance with the sample Cu1.8S-3. We most probably succeeded in stopping the mill quite early in this&#160;case. However, further milling leads to a partial transformation to covellite, and in the case of samples Cu1.8S-1 and Cu1.8S-2, we managed to stop the mill slightly later. According to the reports on the mechanochemical synthesis of SnSe from corresponding elements, the phase-pure orthorhombic SnSe phase was almost exclusively obtained16,26,27. In our case also the presence of SnSe2 phase was observed. Again, its amount differs among the three experiments, and thus, we are of the opinion that there is some interchange between the SnSe and SnSe2 depending on the time that elapsed from the MSR until the stopping of the mill. Nevertheless, the Sn-Se system seems to be more stable&#160;than Cu-S one with regards to the phase composition obtained after MSR, as the appearance of all three XRD patterns is very similar (Figure 3A), unlike in the Cu-S system (Figure 3B). The answers regarding phase compositions during milling could be provided by in situ X-ray monitoring28,29 and we are planning to study these reactions in this way in the future. However, only oscillation milling can be monitored in this way for now (in situ monitoring of planetary ball milling setup is not available yet). The Rietveld refinement of the two selected XRD patterns from both systems confirmed the nanocrystalline character of the products. Metal chalcogenides are usually prepared with the&#160;crystallites on the nanoscale via mechanochemistry16. However, MSR processes are specific, and due to combustion, the crystallite sizes are usually larger than when performing the reaction in a gradual manner, e.g., the ones in Bal&#225;&#382; et al.16 are much larger than the ones in Tsuzuki et al.30. In the case of Cu1.8S, the determined crystallite size of the main digenite phase was either around 63 nm or 39 nm. In the former case, the product was analyzed sooner after the MSR, so the crystallite size is larger. The crystallite sizes reported in this study are larger than 15 nm reported for the CuS obtained after the MSR in25. The SnSe particles were larger than that of Cu1.8S, namely the values larger than 84 nm were observed. These values are significantly larger than 12 nm reported for SnSe synthesized by mechanical alloying for 1 h31. In general, continuing milling after the MSR seems to rapidly diminish the crystallite size. After the MSR event, the crystallite size decreases and can reach similar values to the ones obtained via gradual processes after some time.
The nanostructuring being brought about via the mechanochemical approach is very beneficial for the TE performance of the materials32. Despite the fact, that they are densified by a subsequent step (such as spark plasma sintering), the materials still keep the memory of their original synthetic procedure33. However, it is beyond the scope of this study to analyze and discuss the TE performance of the prepared products.
This protocol shows a simple, environmentally and user-friendly methodology to obtain nanocrystalline materials and even monitor temperature during the process. The critical steps in the protocol are to check if the monitoring device is working properly (step 3.2) and to stop the milling process as soon as possible after the MSR occurrence (step 4.8). The rest is just about characterization and data analysis. For now, there is a limitation about the quick destruction of the sensor, but this can be easily replaced with a new one, as these are very cheap. It would be great if the mill could automatically stop at the moment of MSR, but this has not been solved yet. The solution proposed in this study offers much more detailed temperature monitoring than is available on the market for now. From the synthesis point of view, by just introducing elements, we are capable of producing the powder suitable for TE applications within the second range. Utilizing mechanochemical synthesis to ignite MSRs for diverse materials preparation via simultaneous temperature monitoring might be an interesting topic for future research on a more general level.

Statistically, more than 60% of energy in the world is lost, mostly as waste heat.&#160;Utilizing&#160;the waste heat for thermoelectricity (TE) applications has a great potential. TE offers a suitable method to convert waste heat into electrical energy. Special applications, like electrical energy sources in radioactive thermoelectric generators for space research and/or replacing the old Hg-Zn batteries in cardiac pacemakers, can be mentioned1.
Among various TE materials, chalcogenides belong among the favorites, especially if they are composed of abundant and non-toxic elements. Chalcogenides with tellurium, lead, and germanium content were reported as perspective TE materials in the past, with Bi2Te3 and (Bi,Sb)2Te3 being among the most prominent examples. However, both Bi and Te are rare and/or toxic, making the mass production of TE materials with this composition challenging2. Looking forward to selection among chalcogenides, the new alternatives that bear in mind non-toxicity, earth-abundancy, and TE efficiency are considered. Two systems that fulfill these criteria are copper sulfides Cu2-xS and tin selenide SnSe.
Copper sulfides are present frequently in nature as minerals in several compositions, with chalcocite Cu2S and covellite CuS as border members. In between, several&#160;non-stoichiometric&#160;compounds exist3. Among them, Cu1.97S and Cu1.98S, with interesting properties, were already synthesized by directly melting the elements Cu and S4,5.&#160;&#160;Also, digenite Cu1.8S is particularly interesting for thermoelectrics.
Tin selenide SnSe represents a high TE figure among chalcogenides. The synthesis at&#160;1223 K for over 9.5 h led to its ultralow thermal conductivity and subsequent high thermoelectric efficiency6. Accompanying phenomena were not studied.
Synthesis routes of copper sulfides and tin selenides encompass mostly high-temperature treatment of reaction precursors4,7,8,9,10. However, there are also alternative, more environmentally sound synthesis routes such as mechanochemical synthesis3,11,12,13. The&#160;mechanochemical synthesis of chalcogenides&#160;from elements can, under some circumstances, occur as a mechanically induced self-propagating reaction (MSR), which is a combustion-like process instantly yielding the products in a very short timeframe14,15,16. For both systems reported in this study, the MSR was reported- for Cu1.8S, it was done instantly, albeit the Cu:S ratio 1.6 needed to be used due to the volatility of sulfur16,17, and for SnSe, it occurred in about 15 s16.
The ignition of an MSR is accompanied by a sudden increase in temperature and pressure. Upon monitoring these characteristics via specifically engineered milling jars, it is possible to determine the MSR onset. However, the commercially available devices for planetary ball milling monitoring offer only the data collection every 2 s, and due to the location of the sensors, MSR can be detected only via pressure monitoring, neither by temperature one16,18. Moreover, the mentioned system is not transferrable and can only be both purchased and used together with the specifically engineered milling jar, which is both limiting and costly. We have recently developed a transferrable device capable of collecting temperature data every 80 ms19. This advanced measuring system developed for in situ temperature monitoring during mechanochemical synthesis significantly enhances the capabilities over existing commercial solutions. This system employs an NRBG104F3435B2F NTC thermistor, featuring a resistance tolerance of &#177;1% at 25 &#176;C and a beta value tolerance of &#177;1%, ensuring high-precision temperature measurements. With a data capture frequency of every 80 milliseconds, the system provides a high-resolution monitoring crucial for detecting the initiation of MSRs. The thermistor&#39;s high sensitivity to temperature changes, indicated by a steep resistance-temperature relationship, ensures accurate detection of rapid temperature spikes. The temperature sensor is strategically placed within an existing screw mechanism used for pressure release and gas addition, located in the hole of a massive cap. This placement protects the sensor from mechanical collisions and signal noise caused by the milling balls, ensuring stable and reliable temperature readings.&#160;The limitation is that the ball diameter needs to be larger than the hole diameter. With 10 mm balls, there is no problem. The system&#39;s wireless communication capability and robust sealing mechanism prevent material or heat leakage, thereby enhancing the reliability and accuracy of the temperature data collected during the milling process. Designed to be cost-effective and portable, this system represents a significant advancement in the real-time&#160;temperature monitoring of chemical reactions during planetary ball milling, offering critical insights for the optimization of materials synthesis.
This study aims to demonstrate the performance of this newly developed device by monitoring temperature during the mechanochemical synthesis of two selected metal chalcogenides that are interesting for TE applications. Another objective is to show the sustainable, simple, and time-saving character of the mechanochemical synthesis, which is boosted when the reaction occurs as an MSR.

<table><tbody><tr><td>Copper</td><td>Pometon, Germany</td><td>7440-50-8</td><td>Red powder</td></tr><tr><td>D8 Advance diffractometer&amp;nbsp;</td><td>Bruker, Germany</td><td>M88-E03036</td><td>X-ray instrument</td></tr><tr><td>DiffracPlus Evaluation package release</td><td>Bruker, Germany</td><td>DOC-M85-EXX002</td><td>Diffraction analysis software</td></tr><tr><td>Etaben</td><td>Mikrochem, Slovakia</td><td>64-17-5</td><td>solution</td></tr><tr><td>Jedit</td><td>Open Source software</td><td></td><td>Programmer&#039;s text editor</td></tr><tr><td>Project SAV 1.0</td><td></td><td></td><td>Software developed to record data from in situ temeprature monitoring</td></tr><tr><td>Pulverisette P7 planetary mill</td><td>Fritsch, Germany</td><td>07.5000.00</td><td>The milling device, utilized in the synthesis of Cu&lt;sub&gt;1.8&lt;/sub&gt;S and SnSe</td></tr><tr><td>Selenium</td><td>Acros Organic, Germany</td><td>7782-49-2</td><td>Gray powder</td></tr><tr><td>Sulfur</td><td>Sigma Aldrich, Germany</td><td>7704-34-9</td><td>Yellow powder</td></tr><tr><td>Tin</td><td>Merck, Germany</td><td>7440-31-5</td><td>Gray powder</td></tr><tr><td>Topas Academic</td><td>Coelho Software</td><td></td><td>General non-linear least squares software driven by a scripting language. Its main focus is in crystallography, solid state chemistry and optimization.</td></tr></tbody></table>

demonstrating the simplicity and in situ temperature monitoring of the mechanochemical synthesis of metal chalcogenides suitable for thermoelectrics

Mechanochemical synthesis is an extremely useful strategy to reach thermoelectric materials due to its solvent-free one-step character, as the targeted thermoelectricity (TE) materials in a nanocrystalline format can be prepared by mere high-energy milling of elemental precursors. Nevertheless, the subsequent densification method (e.g., spark plasma sintering or hot pressing) is required afterward, similarly to other synthetic methodologies. In this study, the simplicity of mechanochemical synthesis is&#160;presented for two selected metal chalcogenides, namely copper sulfide (Cu1.8S, digenite) and tin selenide (SnSe, svetlanaite), which are known for high ZT values. These compounds can be prepared via a mechanically induced self-propagating reaction (MSR), which is a combustion-like process instantly yielding the products in a very short timeframe (within 1 min). The occurrence of MSR can be well-tracked by in situ temperature monitoring since an abrupt temperature increase occurs at the moment of MSR. We have developed a device which is capable of monitoring the temperature inside the milling jar every 80 ms during planetary ball milling, and it is therefore possible to very precisely track the moment of MSR ignition. The developed device presents an improvement in the monitoring capabilities in comparison with commercially available analogs. This contribution aims to provide a visual insight into all steps, with simple high-energy ball milling of elements to reach TE materials and in situ temperature monitoring being the central points.

The temperature during milling was recorded using Project SAV 1.0 software and plotted accordingly. Figure 3 demonstrates the changes in temperature with milling time. For the Cu1.8S samples (Figure 3A), the ignition times fall within the range of 0-0.6 s. In the sample Cu1.8S-1, the MSR occurred before temperature data collection began. Therefore, when performing the two next experiments (Cu1.8S-2 and 4), data collection was started prior to milling (therefore, the negative time values are present for the two curves in the figure). The ignition of MSR for samples Cu1.8S-1 and Cu1.8S-3 resulted in the maximum temperatures of 45.8 &#176;C and 42.7 &#176;C, respectively. In the latter case, the temperature increased by more than 15 &#176;C at the moment of MSR. In contrast, small temperature increases were observed in samples Cu1.8S-2 and Cu1.8S-4, namely 3.8 &#176;C and 1.0 &#176;C. In Figure 3B, the temperature-time plots for the SnSe samples showing the occurrence of the MSR after 87 s, 89 s, and 97 s, accompanied by temperature increases of about 3.8 &#176;C, 1.5 &#176;C, and 8.0 &#176;C respectively, are shown.
The XRD patterns of 1.6Cu+S and Sn+Se mixtures obtained immediately after the temperature change event, together with the mixed elemental mixtures, are shown in Figure 4. The as-prepared mixed elemental mixtures do not contain any sulfides, just elemental precursors. This means that the energy supplied by a mere mixing with a spatula is not sufficient. Milling the Cu:S mixture with a stoichiometric ratio of 1.6:1&#160;results in the formation of rhombohedral and cubic polymorphs of digenite (Cu1.8S) and hexagonal covellite (CuS) (Figure 4A), in alignment with previous findings3. However, the obtained XRD patterns differ; they either contain sharp diffraction peaks of rhombohedral digenite with marginal amounts of cubic digenite and covellite (sample Cu1.8S-3), or the diffraction peaks are of lower intensity, and the presence of covellite is much more significant (sample Cu1.8S-1 and Cu1.8S-2). The sample Cu1.8S-4 represents a hybrid of these two scenarios, resembling more Cu1.8S-3 sample. In Figure 4B, the three similar XRD patterns of the Sn+Se mixture are shown. The distinct peaks corresponding to the (201), (011), (111), and (221) planes, characteristic of the orthorhombic svetlanaite (SnSe) phase, were identified16. Trace amounts of berndtite (SnSe2), as demonstrated, e.g., by the diffraction peak at 15&#176;, were also formed in all the cases.
In order to get information about the exact phase composition and crystallite size, Rietveld refinements were performed on two XRD patterns from each system (Figure 5). The identified phase composition is provided in Table 2. For both Cu1.8S samples, rhombohedral digenite was identified as the major phase with the content of around 90%. The residual 10% was either split in between covellite, CuS, and cubic Cu1.8S in the case of sample Cu1.8S-4 or belonged to covellite as a whole (sample Cu1.8S-1). The estimated crystallite size of rhombohedral Cu1.8S was 63 &#177; 1 nm and 39 &#177; 1 nm for Cu1.8S-4 and Cu1.8S-1 samples, respectively. In the case of Cu1.8S-1, the estimated crystallite size of CuS was 25 &#177; 1 nm (Table 2).
Regarding the SnSe system, the major desired svetlanaite SnSe phase was present in 84% and 94% of SnSe-1 and -2 samples, respectively. The rest was assigned to the berndtite SnSe2. The estimated crystallite size of SnSe product is 92 &#177; 2 nm and 80 &#177; 1 nm for SnSe-3 and SnSe-2 samples, respectively. In the case of SnSe-3, the crystallite size of SnSe2 admixture was 53 &#177; 5 nm (Table 2).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/67249/67249fig01.jpg" /> 
Figure 1: Necessary equipment and scheme of the temperature monitoring device to ignite MSR. The photographs of (A) Pulverisette 7 premium line planetary micro mill, (B) milling jar&#160;made from tungsten carbide with a volume of 80 mL, 25 pieces of 10 mm of tungsten carbide balls,&#160;rubber sealing and the lid of tungsten carbide jar, (C) device used for the in situ temperature monitoring including electronics and temperature NTC sensor, and (D) the schematic diagram of the working principle of the device. The sensor is equipped with a Li-ion battery. The temperature sensor NTC is supported by microcontroller STM 32 for the operation, and the recorded data is transferred to the PC by using Bluetooth module HC-O5. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/67249/67249fig01large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/67249/67249fig02.jpg" /> 
Figure 2: Appearance of the sample. Photographs of (A) Cu-S mixture before milling, (B) extracted Cu1.8S-1 (Cu1.8S-2 looks the same), (C) extracted Cu1.8S-3 (Cu1.8S-4 looks the same), (D) Sn-Se mixture before milling, and (E) extracted SnSe (all the products SnSe-1-3 look the same). <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/67249/67249fig02large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/67249/67249fig03.jpg" /> 
Figure 3: Temperature changes during milling. (A) Cu-S system: Cu1.8S-1 with the ignition time of 0 s (black), Cu1.8S-2 with the ignition time of 0.08 s (red), Cu1.8S-3 with the ignition time of 0.43 s (magenta), Cu1.8S-4 with the ignition time of 0.6 s (blue). (B) Sn-Se system: SnSe-1 with an ignition time of 87 s (black), SnSe-2 with an ignition time of 89 s (green), and SnSe-3 with an ignition time of 97 s (red). The negative values in part a are due to the fact that the device was started prior to milling in order to catch the very fast reaction occurring immediately after milling initiation. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/67249/67249fig03large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/67249/67249fig04.jpg" /> 
Figure 4: XRD patterns. (A) Cu-S system, Cu1.8S-1 with the ignition time of 0 s (black) and Cu1.8S-2 with the ignition time of 0.08 s (red), Cu1.8S-3 with the ignition time of 0.43 s (navy), Cu1.8S-4 with the ignition time of 0.6 s (blue), mixture&#160;of Cu:S (1.6:1)&#160;before milling&#160;(magenta). (B) Sn-Se system, SnSe-1 was recorded with an ignition time of 87 s (black), SnSe recorded with an ignition time of 89 s (blue), SnSe-3 with an ignition time of 97 s (red), and mixtures of Sn:Se (1:1) (magenta). The identified crystallographic phases together with their ICDD-PDF2 card numbers, are presented in the figure. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/67249/67249fig04large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/67249/67249fig05.jpg" /> 
Figure 5: Rietveld refinement plots. (A) Cu1.8S-1 with the ignition time of 0.08 s. (B) Cu1.8S-4 with the ignition time of 0.6 s. The scattered black bullets are the experimental data, the red and blue lines are calculated, and full difference X-ray diffraction profiles, respectively. The Bragg diffraction of hexagonal CuS, rhombohedral Cu1.8S, and cubic Cu1.8S are depicted by the magenta, light green, and dark green lines, respectively. (C) SnSe-3 with the ignition time of 97 s. (D) SnSe-2 with the ignition time of 89 s. The scattered black bullet depicts the experimental data, the red and blue lines are calculated, and full difference X-ray diffraction profiles, respectively. The Bragg diffraction of SnSe and SnSe2 are depicted by the magenta and dark green lines, respectively. The fitting factors are also provided in the figure. <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/67249/67249fig05large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Material</td>
			<td>Milling chamber volume (mL)</td>
			<td>Milling balls (pieces x diameter in mm)</td>
			<td>Milling&#160;speed (rpm)</td>
			<td rowspan="2"><img alt="Equation 1" src="/files/ftp_upload/67249/67249eq01.jpg" style="margin: auto;" /></td>
		</tr>
		<tr>
			<td>Tungsten carbide (WC)</td>
			<td>80</td>
			<td>25 x 10</td>
			<td>400</td>
		</tr>
	</tbody>
</table>
Table 1: The milling parameters for the synthesis of Cu1.8S and SnSe through the MSR&#160;and the photograph of the&#160;in situ monitoring device mounted on the milling jar.&#8203;
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Sample</td>
			<td rowspan="2">Time until MSR (s)</td>
			<td rowspan="2">Rhombohedral digenite, Cu1.8S</td>
			<td rowspan="2">Cubic digenite, Cu1.8S</td>
			<td rowspan="2">Hexagonal covellite, CuS</td>
		</tr>
		<tr>
			<td>Cu-S system</td>
		</tr>
		<tr>
			<td>Cu1.8S-1</td>
			<td>0</td>
			<td>90 &#177; 1</td>
			<td>-</td>
			<td>10 &#177; 1&#160;</td>
		</tr>
		<tr>
			<td>Cu1.8S-4</td>
			<td>0.6</td>
			<td>92 &#177; 2</td>
			<td>3 &#177; 1</td>
			<td>5 &#177; 1</td>
		</tr>
		<tr>
			<td>Sn-Se system</td>
			<td>Time until MSR (s)</td>
			<td>Orthorhombic&#160; svetlanaite,&#160; SnSe</td>
			<td>Hexagonal &#160;berndtite, SnSe2</td>
			<td></td>
		</tr>
		<tr>
			<td>SnSe-3</td>
			<td>98</td>
			<td>84 &#177; 2</td>
			<td>16 &#177; 2</td>
			<td></td>
		</tr>
		<tr>
			<td>SnSe-2</td>
			<td>89</td>
			<td>94 &#177; 2</td>
			<td>6 &#177; 2</td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 2: MSR ignition time and phase composition (%) of the four selected samples according to Rietveld refinement.

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Here, we present a protocol to synthesize two metal chalcogenides (Cu1.8S and SnSe) suitable for thermoelectrics via an ultrafast (second-range), solvent-free, and one-step mechanochemical synthesis using elemental precursors. Simultaneously, we demonstrate the monitoring of the temperature in the jar during planetary ball milling in situ by the newly developed device.

Mechanochemical synthesis is an extremely useful strategy to reach thermoelectric materials due to its solvent-free one-step character, as the targeted ...

demonstrating-simplicity-situ-temperature-monitoring-mechanochemical

Nanyang Technological University

Research

JoVE Journal

Chemistry

263 Views.  Slovak Academy of Sciences. Here, we present a protocol to synthesize two metal chalcogenides (Cu1.8S and SnSe) suitable for thermoelectrics via an ultrafast (second-range), solvent-free, and one-step mechanochemical synthesis using elemental precursors. Simultaneously, we demonstrate the monitoring of the temperature in the jar during planetary ball milling in situ by the newly developed device. 

Video: Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Thermal Measurement Techniques in Analytical Microfluidic Devices

Thermal measurement techniques have been used for many applications such as thermal characterization of materials and chemical reaction detection. Micromachining techniques allow reduction of the thermal mass of fabricated structures and introduce the possibility to perform high sensitivity thermal measurements in the micro-scale and nano-scale devices. Combining thermal measurement techniques with microfluidic devices allows performing different analytical measurements with low sample consumption and reduced measurement time by integrating the miniaturized system on a single chip. The procedures of thermal measurement techniques for particle detection, material characterization, and chemical detection are introduced in this paper.

Here, we present three protocols for thermal measurements in microfluidic devices.

Thermal measurement techniques have been used for many applications such as thermal characterization of materials and chemical reaction detection. ...

Engineering

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient optical micro-imaging technique which can be used to map and quantify such behavior. Europium thenoyltrifluoroacetonate (EuTFC) has a 612 nm luminescence line whose activation efficiency drops strongly with increasing temperature, due to T-dependent interactions between the Eu3+ ion and the organic chelating compound. This material may be readily coated on to a sample surface by thermal sublimation in vacuum. When the coating is excited with ultraviolet light (337 nm) an optical micro-image of the 612 nm luminescent response can be converted directly into a map of the sample surface temperature. This technique offers spatial resolution limited only by the microscope optics (about 1 micron) and time resolution limited by the speed of the camera employed. It offers the additional advantages of only requiring comparatively simple and non-specialized equipment, and giving a quantitative probe of sample temperature.

Europium thenoyltrifluoroacetonate (EuTFC) has an optical luminescence line at 612 nm, whose activation efficiency decreases strongly with temperature. If a sample coated with a thin film of this material is micro-imaged, the 612 nm luminescent response intensity may be converted into a direct map of sample surface temperature.

Micro-electronic devices often undergo significant self-heating when biased to their typical operating conditions. This paper describes a convenient ...

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and forging. Adoption of this technique is proceeding despite disagreement concerning the underlying mechanism responsible for EAD. The experimental procedure described herein enables a more explicit study compared to previous EAD research by removing thermal effects, which are responsible for disagreement in interpreting previous EAD results. Furthermore, as the procedure described here enables EAD observation in situ and in real time in a transmission electron microscope (TEM), it is superior to existing post-mortem methods that observe EAD effects post-test. Test samples consist of a single crystal copper (SCC) foil having a free-standing tensile test section of nanoscale thickness, fabricated using a combination of laser and ion beam milling. The SCC is mounted to an etched silicon base that provides mechanical support and electrical isolation while serving as a heat sink. Using this geometry, even at high current density (~3,500 A/mm2), the test section experiences a negligible temperature increase (&#60;0.02 &#176;C), thus eliminating Joule heating effects. Monitoring material deformation and identifying the corresponding changes to microstructures, e.g. dislocations, are accomplished by acquiring and analyzing a series of TEM images. Our sample preparation and in situ experiment procedures are robust and versatile as they can be readily utilized to test materials with different microstructures, e.g., single and polycrystalline copper.

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Isolating electrical and thermal effects on electrically assisted deformation (EAD) is very difficult using macroscopic samples. Metallic sample micro- and nanostructures together with a custom test procedure have been developed to evaluate the impact of applied current on the formation without joule heating and evolution of dislocations on these samples.

Electrically assisted deformation (EAD) is increasingly being used to improve the formability of metals during processes such as sheet metal rolling and ...

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for Cu(In,Ga)Se2 Solar Cells

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction of degradation mechanisms and prevention of module field failure can consequently decrease investment risks as well as increase the electricity yield. An improved knowledge level can for these reasons significantly decrease the total costs of PV electricity. 
In order to better understand and minimize the degradation of PV modules, the occurring degradation mechanisms and conditions should be identified. This should preferably happen under combined stresses, since modules in the field are also simultaneously exposed to multiple stress factors. Therefore, two 'Combined Stress test with in situ measurement' setups have been designed and constructed. These setups allow the simultaneous use of humidity, temperature, illumination, and electrical biases as independently controlled stress factors on solar cells and minimodules. The setups also allow real-time monitoring of the electrical properties of these samples. This protocol presents these setups and describes the experimental possibilities. Moreover, results obtained with these setups are also presented: various examples about the influence of both deposition and degradation conditions on the stability of thin film Cu(In,Ga)Se2 (CIGS) as well as Cu2ZnSnSe4 (CZTS) solar cells are described. Results on the temperature dependency of CIGS solar cells are also presented.

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for CuIn,GaSe2 Solar Cells

Two &#39;Combined Stress test with in situ measurement&#39; setups, which allow real-time monitoring of accelerated degradation of solar cells and modules, were designed and constructed. These setups allow the simultaneous use of humidity, temperature, electrical biases, and illumination as independently controlled stress factors. The setups and various experiments executed are presented.

The levelized cost of electricity (LCOE) of photovoltaic (PV) systems is determined by, among other factors, the PV module reliability. Better prediction ...

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

Low-grade heat is abundantly available in the environment as waste heat. The efficient conversion of low-grade heat into electricity is very difficult. We developed an asymmetric thermoelectrochemical cell (aTEC) for heat-to-electricity conversion under isothermal operation in the charging and discharging processes without exploiting the thermal gradient or the thermal cycle. The aTEC is composed of a graphene oxide (GO) cathode, a polyaniline (PANI) anode, and 1M KCl as the electrolyte. The cell generates a voltage due to the pseudocapacitive reaction of GO when heating from room temperature (RT) to a high temperature (TH, ~40-90 &#176;C), and then current is successively produced by oxidizing PANI when an external electrical load is connected. The aTEC demonstrates a remarkable temperature coefficient of 4.1 mV/K and a high heat-to-electricity conversion efficiency of 3.32%, working at a TH = 70 &#176;C with a Carnot efficiency of 25.3%, unveiling a new promising thermoelectrochemical technology for low-grade heat recovery.

Low-grade heat is abundant, but its efficient recovery is still a great challenge. We report an asymmetric thermoelectrochemical cell using graphene oxide as a cathode and polyaniline as an anode with KCl as the electrolyte. This cell works under isothermal heating, exhibiting a high heat-to-electricity conversion efficiency in low-temperature regions.

Low-grade heat is abundantly available in the environment as waste heat. The efficient conversion of low-grade heat into electricity is very difficult. We ...

In Situ Surface Temperature Measurement in a Conveyor Belt Furnace via Inline Infrared Thermography

Measuring the surface temperature of objects that are processed in conveyor belt furnaces is an important tool in process control and quality assurance. Currently, the surface temperature of objects processed in conveyor belt furnaces is typically measured via thermocouples. However, infrared (IR) thermography presents multiple advantages compared to thermocouple measurements, as it is a contactless, real-time, and spatially resolved method. Here, as a representative proof-of-concept example, an inline thermography system is successfully installed into an IR lamp powered solar firing furnace, which is used for the contact firing process of industrial Si solar cells. This protocol describes how to install an IR camera into a conveyor belt furnace, conduct a customer correction of a factory calibrated IR camera, and perform the evaluation of spatial surface temperature distribution on a target object.

This protocol describes how to install an infrared camera into a conveyor belt furnace, conduct a customer correction of a factory calibrated IR camera, and evaluate the spatial surface temperature distribution of an object of interest. The example objects are industrial silicon solar cells.

Measuring the surface temperature of objects that are processed in conveyor belt furnaces is an important tool in process control and quality assurance. ...

Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope

Gas reactions studied by in situ electron microscopy can be used to capture the real-time morphological and microchemical transformations of materials at length scales down to the atomic level. In situ closed-cell gas reaction (CCGR) studies performed using (scanning) transmission electron microscopy (STEM) can separate and identify localized dynamic reactions, which are extremely challenging to capture using other characterization techniques. For these experiments, we used a CCGR holder that utilizes microelectromechanical systems (MEMS)-based heating microchips (hereafter referred to as &#34;E-chips&#34;). The experimental protocol described here details the method for performing in situ gas reactions in dry and wet gases in an aberration-corrected STEM. This method finds relevance in many different materials systems, such as catalysis and high-temperature oxidation of structural materials at atmospheric pressure and in the presence of various gases with or without water vapor. Here, several sample preparation methods are described for various material form factors. During the reaction, mass spectra obtained with a residual gas analyzer (RGA) system with and without water vapor further validates gas exposure conditions during reactions. Integrating an RGA with an in situ CCGR-STEM system can, therefore, provide critical insight to correlate gas composition with the dynamic surface evolution of materials during reactions. In situ/operando studies using this approach allow&#160;for detailed investigation of the fundamental reaction mechanisms and kinetics that occur at specific environmental conditions (time, temperature, gas, pressure), in real-time, and at high spatial resolution.

Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope

Here, we present a protocol for performing in situ TEM closed-cell gas reaction experiments while detailing several commonly used sample preparation methods.

Gas reactions studied by in situ electron microscopy can be used to capture the real-time morphological and microchemical transformations of materials at ...

Magnetometric Characterization of Redox-Active MOFs Solid-State Electrochemistry

Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks

Electrochemical energy storage has been a widely discussed application of redox-active metal-organic frameworks (MOFs) in the past 5 years. Although MOFs show outstanding performance in terms of gravimetric or areal capacitance and cyclic stability, unfortunately their electrochemical mechanisms are not well understood in most cases. Traditional spectroscopic techniques, such as X-ray photoelectron spectroscopy (XPS) and X-ray absorption fine structure (XAFS), have only provided vague and qualitative information about valence changes of certain elements, and the mechanisms proposed based on such information are often highly disputable. In this article, we report a series of standardized methods, including the fabrication of solid-state electrochemical cells, electrochemistry measurements, the disassembly of cells, the collection of MOF electrochemical intermediates, and physical measurements of the intermediates under the protection of inert gases. By using these methods for quantitatively clarifying the electronic and spin state evolution within a single electrochemical step of redox-active MOFs, one can provide clear insight into the nature of electrochemical energy storage mechanisms not only for MOFs, but also for all other materials with strongly correlated electronic structures.

Author Spotlight: Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks  

Ex situ magnetic surveys can directly provide bulk and local information on a magnetic electrode to reveal its charge storage mechanism step by step. Herein, electron spin resonance (ESR) and magnetic susceptibility are demonstrated to monitor the evaluation of paramagnetic species and their concentration in a redox-active metal-organic framework (MOF).

Electrochemical energy storage has been a widely discussed application of redox-active metal-organic frameworks (MOFs) in the past 5 years. Although MOFs ...

Deposition of Bi2Te3 and Sb2Te3 Thin Films on Glass Substrates via RF Sputtering

Fabrication of Bi2Te3 and Sb2Te3 Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique

Through various studies on thermoelectric (TE) materials, thin film configuration gives superior advantages over conventional bulk TEs, including adaptability to curved and flexible substrates. Several different thin film deposition methods have been explored, yet magnetron sputtering is still favorable due to its high deposition efficiency and scalability. Therefore, this study aims to fabricate a bismuth telluride (Bi2Te3) and antimony telluride (Sb2Te3) thin film via the radio frequency (RF) magnetron sputtering method. The thin films were deposited on soda lime glass substrates at ambient temperature. The substrates were first washed using water and soap, ultrasonically cleaned with methanol, acetone, ethanol, and deionized water for 10 min, dried with nitrogen gas and hot plate, and finally treated under UV ozone for 10 min to remove residues before the coating process. A sputter target of Bi2Te3 and Sb2Te3 with Argon gas was used, and pre-sputtering was done to clean the target&#39;s surface. Then, a few clean substrates were loaded into the sputtering chamber, and the chamber was vacuumed until the pressure reached 2 x 10-5 Torr. The thin films were deposited for 60 min with Argon flow of 4 sccm and RF power at 75 W and 30 W for Bi2Te3 and Sb2Te3, respectively. This method resulted in highly uniform n-type Bi2Te3 and p-type Sb2Te3 thin films.

Author Spotlight: Advancements in High-Performance Thermoelectric Thin Films Through Radio Frequency Magnetron Sputtering

The manuscript describes a protocol for radio frequency magnetron sputtering of Bi2Te3 and Sb2Te3 thermoelectric thin films on glass substrates, which represents a reliable deposition method that provides a wide range of applications with the potential for further development.

Demonstrating the Simplicity and In Situ Temperature Monitoring of the Mechanochemical Synthesis of Metal Chalcogenides Suitable for Thermoelectrics

Summary

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Chapters in this video

Thermal Measurement Techniques in Analytical Microfluidic Devices

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

High-resolution Thermal Micro-imaging Using Europium Chelate Luminescent Coatings

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

In Situ Monitoring of the Accelerated Performance Degradation of Solar Cells and Modules: A Case Study for Cu(In,Ga)Se₂ Solar Cells

Asymmetric Thermoelectrochemical Cell for Harvesting Low-grade Heat under Isothermal Operation

In Situ Surface Temperature Measurement in a Conveyor Belt Furnace via Inline Infrared Thermography

Performing In Situ Closed-Cell Gas Reactions in the Transmission Electron Microscope

Magnetometric Characterization of Intermediates in the Solid-State Electrochemistry of Redox-Active Metal-Organic Frameworks

Fabrication of Bi₂Te₃ and Sb₂Te₃ Thermoelectric Thin Films using Radio Frequency Magnetron Sputtering Technique