内华达大学拉斯维加斯（内华达大学拉斯维加斯分校）高压科学与工程中心支持通过能源国家核安全管理局（NNSA）合作协议DE-NA0001982上。这项工作是在高压协作访问小组（HPCAT）（部门16），并在GeoSoilEnviroCARS（GSECARS）（13部门），先进光子源（APS），美国阿贡国家实验室（ANL）。支持HPCAT操作奖由美国能源部国家核安全局号的DE-NA0001974和DOE-BES奖编号DE-FG02-99ER45775，部分仪器由美国国家科学基金会的资助。 GeoSoilEnviroCARS是由美国国家科学基金会地球科学（EAR-0622171）和能源部（DOE）地质大学（DE-FG02-94ER14466）支持。支持APS-BES由美国能源部，合同项下的DE-AC02 06CH11357的。 ，我们感谢GSECARS压缩为使用燃气加载系统。

1。金刚石压砧和垫片准备<ol><li>选择锥形设计12底面尺寸和匹配的一对钻石砧。锥形砧设计宽角度X射线窗口提供选择，允许收取相对较高的分辨率的X射线microdiffraction数据。底面（平面或斜面尖端的钻石砧）被选中的最大目标压力。底面平坦部分的直径范围从1-0.07毫米左右的目标压力从10到200多GPA。 </li><li>金刚石砧定位在匹配的锥形外壳碳化钨座椅和地方两个安装夹具。确保锥下部的金刚石压砧紧紧坐在碳化钨座椅旋转砧用镊子。 </li><li>应用负载（几公斤）的钻石。无间隙应保持钻石和座椅之间。周围砧外circumfer的涂抹少量的胶水高效。 </li><li>在120℃下固化1小时重复上述操作，第二金刚石和阀座。 </li><li>将座位对钻石在两部分的钻石砧细胞的粘。带金刚石头（底面）在靠近（约30微米的距离）。 </li><li>使用立体显微镜和侧身检查铁砧，对齐的平坦的前端金刚石压砧（culets）的横向使用的DAC横向固定螺钉（ 图1a）。 </li><li>轻轻接触，使金刚石头。使用的干涉条纹（ 图1b），可见光在轴向的立体视图，监测砧块的相对倾斜。 </li><li>摇滚顶砧使用DAC顶部螺丝。条纹变得更广泛和"走出去尖底"（ 图1c）表明，钻石相对倾斜下降。在轴向视图中，调整使用的DAC侧面的紧定螺钉的水平对齐（ 图1d）。不结盟的钻石显示没有我消除干扰条纹重叠的边缘（ 图1e）。使用丙酮彻底清洁的钻石。 </li><li>放置一个小的金属箔，作为垫片，两个对齐的钻石之间的技巧和箔连接到DAC体与蜡质材料。建议的垫片材料包括高的屈服强度的金属如铼，不锈钢或钨。典型的箔尺寸为长约5毫米×5毫米见方，厚度为0.15-0.25毫米。垫圈应具有质地细腻，无裂纹。 </li><li> ，同时监测的DAC的总厚度用测微计，转动的DAC螺栓均匀，在小步骤产生的压痕与底面的大小而变化的厚度在约80-20微米的范围内（ 图2a）。 </li><li>的中心钻一个孔的压痕的直径之间的1/2和1/3的底面的大小，使用激光钻孔系统（ 图2b）或电火花加工机13。垫片孔应集中在缩进和垂直于它。 </li><li>仔细清洁垫片使用针和超声波浴，约五分钟乙醇。 </li><li>仔细先用砂纸打磨，然后用丙酮浸泡湿巾清洁钻石提示。重新调整垫片牢固，使用蜡质材料，砧小费。 </li></ol> 2。样品和天然气载入中<ol><li>红宝石的荧光光谱的移位14次，15次，16和金可压缩性17被用作二次压力表。用细尖的钨针，精选一个或两个红宝石球（直径10微米），并将其放置在墙壁上的垫片孔，重复的操作少量精金粉（ 图2c）。定位在垫片上的压力标准不应该与样品接触，以避免不必要的反应和寄生散射效应。执行所有样品装载操作无粘结材料的援助，小晶粒弱粘附针，垫圈或通过静电引力的钻石。 </li><li>用电子天平，权衡纯试剂，用研钵适量调匀比例。 </li><li>将少量的两个对齐的钻石的第二DAC的尖端之间的混合物。按样品用手挤压细胞。粉末会被压缩在一个约10微米厚的铝箔。由于小尺寸的样品，如果起始材料的粉末混合物中的Fe 4 O 5的情况下，它是很难装载到精确的比例，因此，至关重要的是，原料粉末是非常细的（小于1微米）和很好的混合。 </li><li>小心，精尖的钨针，打破了成片的压实粉箔。选择约40微米的大片状。请注意:所加载的样品的大小应小于样品室的目标压力的大小。样品室收缩屁股的embly的设计和材料，填充样品腔室，这是非常高的Ne和He的媒体，我们使用的材料的可压缩性。开始40μm厚和120μm的大装有加压氖（见下文）的样品室收缩至约15微米厚，70微米直径在20 GPa。 </li><li>传输上的钻石的底面的中心的第一DAC的片状。重新组装的DAC的两个部分（ 图2c）。 </li><li>除了所使用的特定的激光波长的吸光度，样品加热效率关键取决于样品的制备。特别是，应很好地绝缘的钻石和垫圈具有均匀的厚度，重要的是要加载示例。这是至关重要的，以确保样品不粘附的导热钻石，这将驱散热量。几粒散粉，几乎不可避免地结束了围绕压片状，通常足以使样本解除从铁砧。的压力传输介质，然后将提供的热绝缘层。 </li><li>填充样品室的压力传输介质。推荐的介质包括预加压（1.7千巴）NE或他因为这两个惰性介质提供准静水条件下，以非常高的压力，除了保温。进行气体装载使用压缩/ GSECARS的气体加载系统，详细别处18。 </li></ol> 3。激光加热和高温X射线衍射一个DAC内的样品的加热是通过应用红外激光器样品通过金刚石砧座。样品被加热到很高的温度，吸收激光辐射。可以混合样品不吸收1,063 nm的辐射吸收和化学惰性材料（例如:铂黑粉）间接激光加热。由于钻石是优越的热导体，首选的做法是使用从砧座表面的热绝缘层（例如:氯化钠，氧化镁或Al 2 O 3）分离样品。然而，吸收材料和绝缘材料会造成额外的寄生散射，并可能与样品发生反应。 在的试验站16IDB的HPCAT的13IDD GSECARS 9，10，11在APS安装线上的激光加热系统的目的是执行加热和在DAC加载的样品的X-射线衍射。典型的X-射线束的能量约30千电子伏和上面的焦斑的大小大约是5×5μm的半峰全宽。红外激光器（YLF，波长为1063 nm），用于加热样品在DAC。一种快速的X射线探测器，如MARCCD和XRD 1621 XN ESPE是利用面积。 <ol><li>固定在水冷铜保持器的DAC。使用脱机系统（远程控制的电动载物台和显微镜），以确定的粗糙的样品的位置坐标。的X-射线束和激光束预对准样本位置的样品台的旋转轴线上。 </li><li>在样品台上安装支架（ 图3），退出和关闭实验站实验室安全程序（这些都需要在实验室进行实验的强制性培训）。 </li><li>远程操作的激光加热和X-射线衍射从实验站内的系统，配有计算机和显示器。位置时，样品的样品台的旋转轴线上，用X-射线测得的样品用X-射线光电二极管吸收的档案。 </li><li>移动的上游侧和下游侧的激光加热中的X-射线束的路径中的光学元件。 </li><li>焦点清晰的观察样品的光学调节加热后视镜，以弥补金刚石砧倾斜。 </li><li>打开激光器，并慢慢增加激光功率传递到样品。 </li><li>当样品开始到g低（ 图4a），收集的热辐射频谱使用的成像摄谱仪。 </li><li>使用可用的软件，以适应观测谱普朗克辐射功能，假设黑身体行为来确定样品的温度19，20。调整激光功率样品的两侧，一起或分开，以达到目标温度上测得的样品的两侧。 </li><li>在加热样品，收集衍射图案来监视消失的原料特征峰（通常是光滑的德拜环）以及外观的新阶段峰值（通常呈点状的图案）。的加热时间取决于所进行的特定的合成的温度和动力学研究。在下面简要介绍的合成的Fe 4 O 5的情况下，合成的速度比该检测系统（秒）。 </li><li>移动样品的X-射线束的平面垂直于为几个微米的，尽可​​能均匀地加热样品的步骤。关闭激光器和光学元件移动的X-射线束路径。 </li></ol> 4。合成后的X-射线衍射数据收集如果合成阶段是稳定的温淬火后，可收集衍射数据，加热后。 X-射线衍射数据被收集在透射几何（通过砧座）。仍然被收集的衍射图案和旋转衍射图案（ω扫描）。后者被收集作为单次旋转的图像（宽角扫描），设置精细的步扫描图像（1度或更小），或大的阶跃扫描的图像（5-10℃）。数据收集策略调整根据可用的beamtime，曝光时间和检测器的读出速度。当使用非常快的探测器时，精细的步扫描的数据可以被收集在每个点的二维网格在不到一个小时。这允许一个完整的和客观的SAMP玲在整个样本空间的倒数。 <ol><li>收集一组仍然在二维网格分布覆盖类似的步长大小的样品区的X-射线束的大小，约5μm的衍射图像。在图4b中的网格8×8 = 64个40微米的样品在采集图像的显示。典型的曝光时间在3-20秒之间的范围内，这取决于上的X-射线通量和样品的散射功率。 </li><li>检查的衍射图像中，选择一组位置最适合于单晶（多晶）和粉末衍射分析。衍射图像显示几个点很可能产生一个或几个晶体，可以提供良好的单晶衍射图案。相应的采样位置，定义为Ay的和z（y和z的平面垂直于光束的水平和垂直坐标），适用于单晶或杂粮分析。型态示出光滑的，或者更常见的是，"参差不齐的"德比ê环，Z，定义为位置，适合粉末衍射分析。 </li><li>使用在样品台上翻译马达，移动到第一个好哦，Z位置。收集的广角衍射图像和一组精细的步ω扫描衍射图（与ω-步长为1度或更小）。使用这些模式单晶或杂粮数据分析。 </li><li>重复为每个选定的好哦，Z位置。 </li><li>使用的样品台翻译马达，移动，Z位置。收集广步ω扫描衍射图像， 即 7张图片，10°步长为70°总开。收集的粉末衍射分析的旋转图像，以补偿低的晶粒典型的LH-DAC样本的统计信息。 </li></ol>

<ol>
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T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=High+pressure+single-crystal+micro+X-ray+diffraction+analysis+with+GSE_ADA/RSV+software.">High pressure single-crystal micro X-ray diffraction analysis with GSE_ADA/RSV software.</a> High Pressure Research. 33, 466-484 (2013).</li><li>Grunbaum, F. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Remark+on+phase+problem+in+crystallography.">Remark on phase problem in crystallography.</a> Proc. Natl. Acad. Sci. U.S.A. 72, 1699-1701 (1975).</li><li>Hauptman, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+phase+problem+of+x-ray+crystallography.">The phase problem of x-ray crystallography.</a> Rep. Progr. Phys. 54, 1427-1454 (1991).</li><li>Buhler, J., Reichstein, Z. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Symmetric+functions+and+the+phase+problem+in+crystallography.">Symmetric functions and the phase problem in crystallography.</a> Amer. Math. 357, 2353-2377 (2005).</li></ol>

所描述的协议必须执行的每一步都非常谨慎，以避免灾难性实验失败的风险通过粉碎铁砧，垫片不稳定和压力损失，无法达到目标温度，样本污染，严重的非hydrostaticity， 等等 。 高温高压合成的最大挑战是X-射线衍射数据的解释，过于广泛的问题，在这里概括。 ，虽然结构性解决方案本质上是一个不平凡的问题，24，25，26，高压数据遭受非常高的背景下，存在寄生散射，吸收效果，峰展宽和重叠，可怜的粮食统计，多相样品等 。因此重要的是收集衍射图案与可能的最高分辨率和冗余。 直到最近，由于技术的局限性和时间的限制，最高压合成使用单一仍然衍射图案ESIS产物进行了表征。这种方法是适用于简单的结构和均匀样品的表征。细测绘的高度集中的光束和使用多技术方法的样本，我们正确地考虑，甚至利用合成的样品中的LH-DAC的晶粒尺寸，传播。构成异质样品的各相的结构性质的表征是在选定的模式进行，优选为单相，更好地接近一个理想的粉末和/或单晶衍射图案。一旦各相的结构参数被很好地定义，它们可以被用来解释最复杂的多相型态。测绘样品的成分，大大提高了我们理解的过程中发生的LH-DAC。虽然需要收集和处理数据的显着努力，一个强大的和完整的结构描述的方法导致"辩相对复杂的样品和结构。

压力可以从根本上改变物质的性能和粘接。地球的地形，组合物，动力学，磁，甚至深刻地绑的气氛组合物的行星的内部，这是非常高的压力和温度下发生的进程。地球深部过程包括地震，火山，热和化学对流和分化。用来合成金刚石和立方氮化硼的超硬材料，如高的压力和温度。高温高压原位 X射线衍射结合的合成，使研究人员能够确定的晶体结构的新材料或新技术的极端重要性高压多。高压的知识结构和性能可以解释行星内部结构和流程，建模在极端条件下，合成材料的性能和设计新材料，achievem的耳鼻喉科材料的行为更广泛的基本的了解。高压阶段的勘探技术上要求由于可控地产生极端的环境条件和探测少量样品在笨重的环境细胞的双重挑战。 甲范围内的材料和技术可以被用来在极端条件下的2，3进行合成。为每个特定的实验的最合适的设备依赖于研究的材料，目标PT，和探测技术。在高压设备中，LH-DAC有最小的样本大小，但然而，能够达到最高静态PT（5毫巴和6,000 K）以上，允许的最高分辨率的X射线结构分析。下面描述的协议，导致发现的Fe 4 O 5 1，适用于范围广泛的材料和合成条件。对LH-DAC是最适合的材料，有效地吸收〜1微米高压同步辐射光束线（ 如 16阿贡国家实验室的先进光子源，美洲开发银行和13 IDD站）提供，合成压力高达5毫巴的激光波长和温度大于约1500 K。相当复杂的结构和多相样品的特点可以与这里提出的战略x射线microdiffraction的。其他技术，例如整个的DAC加热4和局部电阻加热，适用于较低的合成温度。 CO 2激光加热，用波长为10μm左右，是适合加热透明的，红外的YLF激光器的材料，但吸收的CO 2的辐射。多顶砧，活塞缸和巴黎爱丁堡印刷机的，其他设备，如提供必要的中子衍射实验，例如大体积样品。 LH-DAC，发明于1967年6，7，8，高压为generated技巧两个反对的钻石砧之间放置一个小样本。安装在同步实验站9，10，11，在激光加热系统，激光束的传递加热斑点而辉煌的X-射线束聚焦在样品上从两侧通过金刚石砧座。吸收的激光的样品被加热，而X-射线衍射是用来监视对合成过程的。通过激光加热样品发出的热辐射取决于温度。用于收集从样品的两侧的热发射光谱拟合光谱的的普朗克辐射的功能，假设黑色车身行为8，计算出样品的温度。 辉煌的同步辐射X射线束，精度高，机动阶段和快速X射线探测器，可在专用同步辐射实验站进行合成产品在LH-DAC的晶体结构分析秒。我们收集X射线衍射数据在2D网格和自定义的数据收集策略，根据至米粒大小。这种方法允许:一）样品的成分映射;二）取得单晶，粉末多晶衍射技术结合强大的数据分析复杂多相样品。

<table border="0" cellpadding="0" cellspacing="0" width="568">
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		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">diamond anvils</td>
			<td style="width:119px;">Almax Easylab</td>
			<td style="width:136px;">N/A</td>
			<td style="width:119px;"></td>
		</tr>
		<tr height="105">
			<td height="105" style="height:105px;width:195px;">WC seats</td>
			<td style="width:119px;">Almax Easylab</td>
			<td style="width:136px;">N/A</td>
			<td style="width:119px;">The conical housing needs to match the conical shape of the anvil bottom</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">SX-165 CCD</td>
			<td style="width:119px;">Marresearch</td>
			<td style="width:136px;"></td>
			<td style="width:119px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">XRD 1621 xN ES</td>
			<td style="width:119px;">Perkin Elmer</td>
			<td style="width:136px;"></td>
			<td style="width:119px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:195px;">W needle</td>
			<td style="width:119px;">Ted pella, Inc</td>
			<td style="width:136px;">MT26020</td>
			<td style="width:119px;"></td>
		</tr>
	</tbody>
</table>

synthesis and microdiffraction at extreme pressures and temperatures

广泛的用途，如深行星的内饰，设计具有新颖性能的材料，结构和流程确定为高压化合物和多晶型研究，了解暴露于很高的应力，爆炸或影响材料的力学行为。在极端的压力和温度条件下材料的合成和结构分析需要显着的技术挑战。在激光加热的钻石砧细胞（LH-DAC），产生很高的压力被迫互相对抗的两个对立的钻石砧的提示;重点红外激光束通过钻石，闪耀之间，可以达到非常高的温度下对样品吸收激光辐射。当安装LH-DAC同步辐射光束线，提供了极其辉煌的X射线辐射，可以在极端条件下材料的结构原位探测LH-DAC的样品，虽然很小，可以显示喜ghly可变粒度，相和化学成分。为了获得高分辨率的结构分析和最全面的表征样品，我们在2D网格收集衍射数据，并结合粉末，单晶和杂粮衍射技术。将会显示一个新的氧化铁，铁4 O 5 1的合成中得到的有代表性的结果。

我们表明获得的的代表microdiffraction数据根据反应的赤铁矿和铁的混合物在高温高压下合成的Fe 4 O 5: <img src="/files/ftp_upload/50613/50613eq1.jpg" alt="公式1" width="450px" fo:content-width="4in" /> 图5示出从B地点的粉末衍射图案。尽管它们被收集间隔为几微米，模式有显着差别。在一个特定的点（ 图5a）合成的Fe 4 O 5并没有出现，相反，我们得到方铁矿（FeO）含量。大概是由于局部高铁/ O比稍高本地/赤铁矿铁比，或由热引起的化学梯度。除了 ​​铁4 O 5和氖，在图5b中示出的图案光滑的德拜环细粒的未再结晶赤铁矿，该反应在这里并不完整，最有可能是由于非均匀加热。 图5c中的模式是一个点，反应完成后，产生几乎纯的Fe 4 O 5的代表。数据处理采用21 FIT2D玉22。 图6示出的单晶衍射图案，导致发现的Fe 4 O 5。该模式是使用索引GSE_ADA 23（ 图6a）和呼吸道合胞病毒（ 图6b）。粉末衍射数据一样，遭受单晶衍射数据测量时，在DAC分辨率和低强度的可靠性限制。然而，三维数据的性质允许更健壮的解释。 <img alt="图1" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig1.jpg" width="500px" /><b转/&gt; 图1。拍摄的显微照片在金刚石砧块对应的不同步骤。金刚石头的侧视图，示出横向大致对齐的提示（一 ）。轴向视图显示干涉条纹倾斜culets（B，C），横向错位砧（D），对齐钻石（E） <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig1highres.jpg" target="_blank">点击此处查看大图</a> 。 <img alt="图2" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig2.jpg" width="500px" /> 图2。激光束显微缩进垫片（一），钻了一个洞在垫圈（b）中，样品室，样品和压力标记（三） <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig2highres.jpg" target="_blank">点击这里查看大图</a> </A&gt;。 <img alt="图3" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig3.jpg" width="500px" /> 图3。卡通表示的LH-DAC系统结合微聚焦X-射线衍射的激光束（红色）被传递到样品通过两个相对的砧座。加热样品发出的热辐射（白色），从双方所收集的光谱仪进行温度测定。同步加速器光束（蓝色），用激光束对准，允许X-射线衍射数据收集从中央加热点。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig3highres.jpg" target="_blank">点击此处查看大图</a> 。 <img alt="图4" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig4.jpg" width="500px" /> 图4。发光的样品一个DAC发光TH在可见光范围内，而主要依托辐射加热红外激光（a）和电网整个样品区（B）收集的X射线数据。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig4highres.jpg" target="_blank">点击这里查看大图</a> 。 <img alt="图5" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig5.jpg" width="500px" /> 图5。收集从不同的位置装入的铁和赤铁矿的混合物在14 GPa和加热后，在大约1700 K。选择粉末衍射图案如图中箭头颜色编码的衍射线，在这三种模式中的主要阶段:1）氖和方铁矿; 二）铁4 O 5，霓虹灯和赤铁矿; 三）铁4 O 5和霓虹灯。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig5highres.jpg" target="_blank">点击这里查看大</a>呃图像。 <img alt="图6" fo:content-width="6in" src="/files/ftp_upload/50613/50613fig6.jpg" width="500px" /> 图6。索引单晶衍射图样的Fe 4 O 5 图1（a）。衍射峰在的相互空间和晶胞（B）。 <a href="https://www-jove-com.remotexs.ntu.edu.sg/files/ftp_upload/50613/50613fig6highres.jpg" target="_blank">点击这里查看大图</a> 。

Watch this Scientific Journal Video about Synthesis and Microdiffraction at Extreme Pressures and Temperatures at JoVE.com

Synthesis and Microdiffraction at Extreme Pressures and Temperatures

激光加热金刚石压腔结合同步微衍射技术使研究人员能够探索的性质和性能的新阶段，无论在极端的压力和温度（PT）的条件。其特征在于异构的样品可以<em在原位</em&gt;高压下二维绘图和综合性粉末，单晶和杂粮衍射方法。

在极端的压力和温度的合成和Microdiffraction

High pressure compounds and polymorphs are investigated for a broad range of purposes such as determine structures and processes of deep planetary ...

synthesis-and-microdiffraction-at-extreme-pressures-and-temperatures

Nanyang Technological University

Research

JoVE Journal

Engineering

11.1K 次观看.  University of Nevada, Las Vegas. 激光加热金刚石压腔结合同步微衍射技术使研究人员能够探索的性质和性能的新阶段，无论在极端的压力和温度（PT）的条件。其特征在于异构的样品可以

视频: Synthesis and Microdiffraction at Extreme Pressures and Temperatures

Micropunching Lithography for Generating Micro- and Submicron-patterns on Polymer Substrates

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of low weight, easy tailoring of properties and a wide spectrum of applications2,3. Due to sensitivity of conducting polymers to environmental conditions (e.g., air, oxygen, moisture, high temperature and chemical solutions), lithographic techniques present significant technical challenges when working with these materials4. For example, current photolithographic methods, such as ultra-violet (UV), are unsuitable for patterning the conducting polymers due to the involvement of wet and/or dry etching processes in these methods. In addition, current micro/nanosystems mainly have a planar form5,6. One layer of structures is built on the top surfaces of another layer of fabricated features. Multiple layers of these structures are stacked together to form numerous devices on a common substrate. The sidewall surfaces of the microstructures have not been used in constructing devices. On the other hand, sidewall patterns could be used, for example, to build 3-D circuits, modify fluidic channels and direct horizontal growth of nanowires and nanotubes.
A macropunching method has been applied in the manufacturing industry to create macropatterns in a sheet metal for over a hundred years. Motivated by this approach, we have developed a micropunching lithography method (MPL) to overcome the obstacles of patterning conducting polymers and generating sidewall patterns. Like the macropunching method, the MPL also includes two operations (Fig. 1): (i) cutting; and (ii) drawing. The "cutting" operation was applied to pattern three conducting polymers4, polypyrrole (PPy), Poly(3,4-ethylenedioxythiophen)-poly(4-styrenesulphonate) (PEDOT) and polyaniline (PANI). It was also employed to create Al microstructures7. The fabricated microstructures of conducting polymers have been used as humidity8, chemical8, and glucose sensors9. Combined microstructures of Al and conducting polymers have been employed to fabricate capacitors and various heterojunctions9,10,11. The "cutting" operation was also applied to generate submicron-patterns, such as 100- and 500-nm-wide PPy lines as well as 100-nm-wide Au wires. The "drawing" operation was employed for two applications: (i) produce Au sidewall patterns on high density polyethylene (HDPE) channels which could be used for building 3D microsystems12,13,14, and (ii) fabricate polydimethylsiloxane (PDMS) micropillars on HDPE substrates to increase the contact angle of the channel15.

A micropunching lithography approach is developed to generate micro- and submicron-patterns on top, sidewall and bottom surfaces of polymer substrates. It overcomes the obstacles of patterning conducting polymers and generating sidewall patterns. This method allows rapid fabrication of multiple features and is free of aggressive chemistry.

Micropunching为微型和亚微米模式聚合物基板上生成的光刻

Conducting polymers have attracted great attention since the discovery of high conductivity in doped polyacetylene in 19771. They offer the advantages of ...

科研

工程学

Angle-resolved Photoemission Spectroscopy At Ultra-low Temperatures

The physical properties of a material are defined by its electronic structure. Electrons in solids are characterized by energy (&omega;) and momentum (k) and the probability to find them in a particular state with given &omega; and k is described by the spectral function A(k, &omega;). This function can be directly measured in an experiment based on the well-known photoelectric effect, for the explanation of which Albert Einstein received the Nobel Prize back in 1921. In the photoelectric effect the light shone on a surface ejects electrons from the material. According to Einstein, energy conservation allows one to determine the energy of an electron inside the sample, provided the energy of the light photon and kinetic energy of the outgoing photoelectron are known. Momentum conservation makes it also possible to estimate k relating it to the momentum of the photoelectron by measuring the angle at which the photoelectron left the surface. The modern version of this technique is called Angle-Resolved Photoemission Spectroscopy (ARPES) and exploits both conservation laws in order to determine the electronic structure, i.e. energy and momentum of electrons inside the solid. In order to resolve the details crucial for understanding the topical problems of condensed matter physics, three quantities need to be minimized: uncertainty* in photon energy, uncertainty in kinetic energy of photoelectrons and temperature of the sample.
In our approach we combine three recent achievements in the field of synchrotron radiation, surface science and cryogenics. We use synchrotron radiation with tunable photon energy contributing an uncertainty of the order of 1 meV, an electron energy analyzer which detects the kinetic energies with a precision of the order of 1 meV and a He3 cryostat which allows us to keep the temperature of the sample below 1 K. We discuss the exemplary results obtained on single crystals of Sr2RuO4 and some other materials. The electronic structure of this material can be determined with an unprecedented clarity.

The overall goal of this method is to determine the low-energy electronic structure of solids at ultra-low temperatures using Angle-Resolved Photoemission Spectroscopy with synchrotron radiation.

在极低的温度下角分辨光电子能谱

The physical properties of a material are defined by its  electronic structure. Electrons in solids are characterized by energy (&omega;)  and momentum ...

Synthesis and Operation of Fluorescent-core Microcavities for Refractometric Sensing

This paper discusses fluorescent core microcavity-based sensors that can operate in a microfluidic analysis setup. These structures are based on the formation of a fluorescent quantum-dot (QD) coating on the channel surface of a conventional microcapillary. Silicon QDs are especially attractive for this application, owing in part to their negligible toxicity compared to the II-VI and II-VI compound QDs, which are legislatively controlled substances in many countries. While the ensemble emission spectrum is broad and featureless, an Si-QD film on the channel wall of a capillary features a set of sharp, narrow peaks in the fluorescence spectrum, corresponding to the electromagnetic resonances for light trapped within the film. The peak wavelength of these resonances is sensitive to the external medium, thus permitting the device to function as a refractometric sensor in which the QDs never come into physical contact with the analyte. The experimental methods associated with the fabrication of the fluorescent-core microcapillaries are discussed in detail, as well as the analysis methods. Finally, a comparison is made between these structures and the more widely investigated liquid-core optical ring resonators, in terms of microfluidic sensing capabilities.

Fluorescent-core microcavity sensors employ a high-index quantum-dot coating in the channel of silica microcapillaries. Changes in the refractive index of fluids pumped into the capillary channel cause shifts in the microcavity fluorescence spectrum that can be used to analyze the channel medium.

折光传感荧光芯微腔的合成和操作

This paper discusses  fluorescent core microcavity-based sensors that can operate in a microfluidic  analysis setup. These structures are based on the ...

High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.

高灵敏度核磁共振的千兆帕斯卡压力:一种新的工具，用于极端条件下探测电子和化工凝聚态的性质

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their ...

Synthesis and Characterization of High c-axis ZnO Thin Film by Plasma Enhanced Chemical Vapor Deposition System and its UV Photodetector Application

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto silicon (Si) substrates via different synthesized temperatures by using plasma enhanced chemical vapor deposition (PECVD) system. The effects of different synthesized temperatures on the crystal structure, surface morphologies and optical properties have been investigated. The X-ray diffraction (XRD) patterns indicated that the intensity of (0002) diffraction peak became stronger with increasing synthesized temperature until 400 oC. The diffraction intensity of (0002) peak gradually became weaker accompanying with appearance of (10-10) diffraction peak as the synthesized temperature up to excess of 400 oC. The RT photoluminescence (PL) spectra exhibited a strong near-band-edge (NBE) emission observed at around 375 nm and a negligible deep-level (DL) emission located at around 575 nm under high c-axis ZnO thin films. Field emission scanning electron microscopy (FE-SEM) images revealed the homogeneous surface and with small grain size distribution. The ZnO thin films have also been synthesized onto glass substrates under the same parameters for measuring the transmittance.
For the purpose of ultraviolet (UV) photodetector application, the interdigitated platinum (Pt) thin film (thickness ~100 nm) fabricated via conventional optical lithography process and radio frequency (RF) magnetron sputtering. In order to reach Ohmic contact, the device was annealed in argon circumstances at 450 oC by rapid thermal annealing (RTA) system for 10 min. After the systematic measurements, the current-voltage (I-V) curve of photo and dark current and time-dependent photocurrent response results exhibited a good responsivity and reliability, indicating that the high c-axis ZnO thin film is a suitable sensing layer for UV photodetector application.

We offered a method to directly synthesize high c-axis (0002) ZnO thin film by plasma enhanced chemical vapor deposition. The as-synthesized ZnO thin film combined with Pt interdigitated electrode was used as sensing layer for ultraviolet photodetector, showing a high performance through a combination of its good responsivity and reliability.

合成和高c轴ZnO薄膜等离子体的特性增强化学气相沉积系统及其紫外探测器的应用

In this study, zinc oxide (ZnO) thin films with high c-axis (0002) preferential orientation have been successfully and effectively synthesized onto ...

Synthesis and Functionalization of 3D Nano-graphene Materials: Graphene Aerogels and Graphene Macro Assemblies

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. Additionally, most reported graphene assemblies are held together through physical interactions (e.g., van der Waals forces) rather than chemical bonds, which limit their mechanical strength and conductivity. This video method details recently developed strategies to fabricate mass-producible, graphene-based bulk materials derived from either polymer foams or single layer graphene oxide. These materials consist primarily of individual graphene sheets connected through covalently bound carbon linkers. They maintain the favorable properties of graphene such as high surface area and high electrical and thermal conductivity, combined with tunable pore morphology and exceptional mechanical strength and elasticity. This flexible synthetic method can be extended to the fabrication of polymer/carbon nanotube (CNT) and polymer/graphene oxide (GO) composite materials. Furthermore, additional post-synthetic functionalization with anthraquinone is described, which enables a dramatic increase in charge storage performance in supercapacitor applications.

This video method describes the synthesis of high surface area, monolithic 3D graphene-based materials derived from polymer precursors as well as single layer graphene oxide.

合成和3D纳米石墨烯材料的功能化:石墨烯气凝胶和石墨烯宏组件

Efforts to assemble graphene into three-dimensional monolithic structures have been hampered by the high cost and poor processability of graphene. ...

Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems

This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the presence of carbon nanotubes. These nanowires are extreme in the sense that they are the limit of miniaturization of nanowires and their behavior is not always a simple extrapolation of the behavior of larger nanowires as their diameter decreases. The paper then describes the methods required to obtain Raman spectra from extreme nanowires and the fact that due to the van Hove singularities that 1D systems exhibit in their optical density of states, that determining the correct choice of photon excitation energy is critical. It describes the techniques required to determine the photon energy dependence of the resonances observed in Raman spectroscopy of 1D systems and in particular how to obtain measurements of Raman cross-sections with better than 8% noise and measure the variation in the resonance as a function of sample temperature. The paper describes the importance of ensuring that the Raman scattering is linearly proportional to the intensity of the laser excitation intensity. It also describes how to use the polarization dependence of the Raman scattering to separate Raman scattering of the encapsulated 1D systems from those of other extraneous components in any sample.

The paper describes a method for producing extreme nanowires by melt infiltration into carbon nanotubes and how 1D systems may be characterized and investigated using Resonance Raman Spectroscopy to determine vibrational and optical excitation energies.

至尊纳米线和其他维系统的共振拉曼光谱

This paper briefly describes how nanowires with diameters corresponding to 1 to 5 atoms can be produced by melting a range of inorganic solids in the ...

Colloidal Synthesis of Nanopatch Antennas for Applications in Plasmonics and Nanophotonics

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic nanoscale patch antennas. This includes a detailed procedure for the fabrication of thin films with a well-controlled thickness over macroscopic areas using layer-by-layer deposition of polyelectrolyte polymers, namely poly(allylamine) hydrochloride (PAH) and polystyrene sulfonate (PSS). These polyelectrolyte spacer layers serve as a dielectric gap in between silver nanocubes and a gold film. By controlling the size of the nanocubes or the gap thickness, the plasmon resonance can be tuned from about 500 nm to 700 nm. Next, we demonstrate how to incorporate organic sulfo-cyanine5 carboxylic acid (Cy5) dye molecules into the dielectric polymer gap region of the nanopatch antennas. Finally, we show greatly enhanced fluorescence of the Cy5 dyes by spectrally matching the plasmon resonance with the excitation energy and the Cy5 absorption peak. The method presented here enables the fabrication of plasmonic nanopatch antennas with well-controlled dimensions utilizing colloidal synthesis and a layer-by-layer dip-coating process with the potential for low cost and large-scale production. These nanopatch antennas hold great promise for practical applications, for example in sensing, ultrafast optoelectronic devices and for high-efficiency photodetectors.

A protocol for the colloidal synthesis of silver nanocubes and fabrication of plasmonic nanoscale patch antennas with sub-10 nm gaps is presented.

在等离子体激元和纳米光子学应用Nanopatch天线的合成胶体

We present a method for colloidal synthesis of silver nanocubes and the use of these in combination with a smooth gold film, to fabricate plasmonic ...

A Simple Dewar/Cryostat for Thermally Equilibrating Samples at Known Temperatures for Accurate Cryogenic Luminescence Measurements

The design and operation of a simple liquid nitrogen Dewar/cryostat apparatus based upon a small fused silica optical Dewar, a thermocouple assembly, and a CCD spectrograph are described. The experiments for which this Dewar/cryostat is designed require fast sample loading, fast sample freezing, fast alignment of the sample, accurate and stable sample temperatures, and small size and portability of the Dewar/cryostat cryogenic unit. When coupled with the fast data acquisition rates of the CCD spectrograph, this Dewar/cryostat is capable of supporting cryogenic luminescence spectroscopic measurements on luminescent samples at a series of known, stable temperatures in the 77-300 K range. A temperature-dependent study of the oxygen quenching of luminescence in a rhodium(III) transition metal complex is presented as an example of the type of investigation possible with this Dewar/cryostat. In the context of this apparatus, a stable temperature for cryogenic spectroscopy means a luminescent sample that is thermally equilibrated with either liquid nitrogen or gaseous nitrogen at a known measureable temperature that does not vary (&#916;T &#60; 0.1 K) during the short time scale (~1-10 sec) of the spectroscopic measurement by the CCD. The Dewar/cryostat works by taking advantage of the positive thermal gradient dT/dh that develops above liquid nitrogen level in the Dewar where h is the height of the sample above the liquid nitrogen level. The slow evaporation of the liquid nitrogen results in a slow increase in h over several hours and a consequent slow increase in the sample temperature T over this time period. A quickly acquired luminescence spectrum effectively catches the sample at a constant, thermally equilibrated temperature.

A simple liquid nitrogen Dewar/cryostat apparatus comprised of a small fused silica optical Dewar, a thermocouple, and a charge-coupled device (CCD) spectrograph are described. The experiments for which this Dewar/cryostat is designed require fast sample loading, freezing, and alignment, accurate and stable sample temperatures, and small size/portability.

一个简单的杜瓦瓶/低温恒温器的热的样品配平在为准确低温发光测量已知温度

The design and operation of a simple liquid nitrogen Dewar/cryostat apparatus based upon a small fused silica optical Dewar, a thermocouple assembly, and ...

Synthesis of Ionic Liquid Based Electrolytes, Assembly of Li-ion Batteries, and Measurements of Performance at High Temperature

The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion batteries for use in devices operating at elevated temperatures require thermally stable and non-flammable electrolytes. Ionic liquids (ILs), which are non-flammable, non-volatile, thermally stable molten salts, are an ideal replacement for flammable and low boiling point organic solvent electrolytes currently used today. We herein describe the procedures to: 1) synthesize mono- and di-phosphonium ionic liquids paired with chloride or bis(trifluoromethane)sulfonimide (TFSI) anions; 2) measure the thermal properties and stability of these ionic liquids by differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA); 3) measure the electrochemical properties of the ionic liquids by cyclic voltammetry (CV); 4) prepare electrolytes containing lithium bis(trifluoromethane)sulfonamide; 5) measure the conductivity of the electrolytes as a function of temperature; 6) assemble a coin cell battery with two of the electrolytes along with a Li metal anode and LiCoO2 cathode; and 7) evaluate battery performance at 100 &#176;C. We additionally describe the challenges in execution as well as the insights gained from performing these experiments.

Here, we describe protocols to prepare phosphonium-based ionic liquid and lithium bis(trifluoromethane)sulfonimide salt electrolytes, and assemble a non-flammable and high temperature functioning lithium-ion coin cell battery.

离子液体基电解质的合成，装配锂离子电池，并在高温性能的测量

The chemical instability of the traditional electrolyte remains a safety issue in widely used energy storage devices such as Li-ion batteries. Li-ion ...