这项工作得到了美国海军研究实验室基础研究计划的ASEE-NRL博士后研究金和海军研究部的支持。作者感谢C. Kindle在NRL的技术支持。

Si框架的微加工<ol><li>在180μm厚的Si晶片上的旋涂（3000rpm和30s）SPR220-7光致抗蚀剂（PR）。使用足够的PR完全涂覆晶片。晶圆的晶面取向并不重要。 </li><li>在60℃下用PR层（约7.5μm厚）将晶片烘烤2分钟，然后在115℃下在热板上烘烤90秒。 </li><li>通过图案化的铬/玻璃光掩模将PR层暴露于紫外线，允许光通过它来限定Si框架的形状。对本步骤和下一步使用标准光刻设备和工艺（ 图2a-b ）。 </li><li>通过在未稀释的MF 24A或MF 319中将具有PR的Si晶片浸入其中约1分钟（ 图2c ）来显影通过光掩模曝光的图案。在步骤1.6期间，图案化的PR层用作掩模。 </li><li>将180μm厚的Si晶片结合到厚度为500μm的支撑Si wafer使用低熔点临时粘合剂以便于处理（详见材料表 ）。使用热板（70°C）在玻璃皿中加热粘合剂，并使用足够的粘合剂涂覆支撑晶片。然后轻轻地将180μm厚的Si晶片压在500μm厚的晶片上（ 图2d ）。 </li><li> 从上方蚀刻顶部的硅晶片，制成独立的结构。使用任何数量的市售电感耦合等离子体反应离子蚀刻系统，其使用Bosch工艺与SF 6和C 4 F 8气体进行蚀刻步骤。在博世工艺中，钝化层沉积和等离子体蚀刻的交替循环导致深刻蚀刻的沟槽，具有大多数完好的侧壁）（图2e）。 <ol><li>开始沉积期间SF 6和C 4 F 8的3和100sccm流动5秒和100和2.5sccm的SF 6和C 4 F <sub蚀刻时分别为8s，7s。根据需要调整仪器相关参数（流速，气体之间的比例和沉积和蚀刻步骤的时间间隔）。 </li></ol></li><li>每20分钟，使用轮廓仪测量蚀刻沟槽的深度，以校准特定于仪器和蚀刻配方的蚀刻速率。 </li><li>通过使用过夜丙酮浸泡去除临时粘合剂和PR，分离支撑硅晶片并清洁薄Si晶片（ 图2f ）。然后用去离子（DI）水彻底冲洗薄晶片。 </li><li>使用任何市售的具有SiH 4 ，N 2 O和N 2气体的等离子体增强化学气相沉积（PECVD）系统（ 图2g ），在Si框架两侧在300℃下沉积SiO 2绝缘层。使用标准SiO 2沉积配方， 例如 ，使用170sccm的5％SiH 4和710sccm的N 2 O沉积2-3μm厚的SiO 2层。 </li><li>打破将各个矩形Si框架连接到周围结构的接头。在光学显微镜下使用尖锐的镊子（ 图2h ）。 </li></ol> 2.金属样品的激光图案<ol><li>切成5.0厘米×5.0厘米的铜箔（纯度99.99％;参见表格材料 ），并用胶带将其粘贴到载玻片上。双面旋涂一层厚1公分的PR。虽然可以通过激光技术切割宽范围厚度（高达100μm）的箔片，但是这里使用两种不同的厚度（13μm和25μm）进行演示。使用足够的PR完全涂覆表面。将PR在115°C烘烤2分钟。需要PR以便保护铜箔的表面免受在激光切割步骤期间产生的碎屑，并允许对样品束进行化学蚀刻（参见步骤2.4）而不影响第e表面的箔。 </li><li>使用具有约90ns脉冲宽度的50kHz的355nm，10瓦，固态，三倍频Nd:YVO 4脉冲激光，切割5个4个单独样品的阵列，每个样品由4mm长的铜框架1 mm宽（ 图3b ）。 </li><li>在铜箔表面调整激光束的能量为65 mJ / cm 2 。这提供足够的激光能量以两次通过铜切割，而不会过度加热和/或损坏相邻的铜。每个样品的图案由Galvo扫描镜产生，该扫描镜扫描激光束以切割每次产生20个样品的铜箔（ 图3a ）。将激光切割样品光束的宽度从30μm（对于13μm厚的箔）调整到50μm（对于25μm厚的箔）。 </li><li>通过将样品阵列浸入40-60℃的40％液体氯化铁中30秒（对于13微米厚的箔）或40秒（对于t他25微米厚的箔）以去除潜在损坏的激光切割边缘，减小单个样品波束在20微米以下的宽度（ 图3c ），并产生光滑的边缘轮廓。 </li><li>将阵列浸入第一丙酮分离的溶剂浴中，然后用甲醇，然后用异丙醇，然后用氮气干燥，除去保护性光致抗蚀剂。将样品阵列存放在干燥氮气干燥器中。上述制造步骤的截面示意图如图3d所示。 </li><li>使用激光切割样品阵列周围的盒子，将其从铜箔的其余部分释放出来。 </li></ol>装配和原位 TEM实验<ol><li>用小型剪刀分离个体标本（包括铜框）。在硅框架上放置少量银环氧树脂，并在光学显微镜下小心地对准样品，使样品计数器跨越中心的窄间隙e框架（ 图4a ）。 </li><li>与步骤3.1类似，用银环氧树脂将银线（直径50μm）连接到样品的两端（ 图5c ）。 </li><li>使用聚焦离子束（FIB）铣削，以创建具有多个肩部的纳米尺度表面（100nm×10μm×10μm）。逐渐变厚的横截面远离规格部分意味着产生电流密度的平滑过渡，在规格部分中更均匀的电流密度，并且使任何给定肩部处的局部加热最小化。为了最小化损坏，在铜样品的最终铣削过程中，使用降低的加速电压（5 kV）和电流（&lt;80 pA）。使用扫描电子显微镜（SEM）图像（ 图4b-e和5b ）测量量规的横截面面积。 </li><li>通过激光切割，FIB或小型剪刀去除标本框架（参见图4a的插图）。虽然不是在图像的情况下，位置o切割应理想地远离仪表部分，以尽可能减少仪表部分的材料损坏。 </li><li>在光学显微镜下将MEMTS安装到单个倾斜应变TEM支架（参见表格 ）上，然后使用螺栓和非导电垫圈将其连接。垫圈用于防止装配过程中的不必要的扭转。使用50 W CO 2激光系统使用硬质纤维电气级片材图案化的垫圈（0.5毫米厚）（ 参见表中激光切割中的具体参数）。 </li><li>使用银导电环氧树脂将步骤3.2中的银线连接到TEM支架上的金属针（ 图5a ）上。 </li><li>使用手持式或台式万用表检查MEMTS（ 图1中的 B和C）上的电阻，以验证仪表部分是否损坏。电阻应小于100Ω。还测量MEMT之间的电阻S和电接地的TEM样品架，以确认样品和TEM支架之间没有电气串扰。如果样品隔离，测得的电阻应大于10MΩ。 </li><li>将具有MEMTS的TEM支架放入TEM进行原位实验。 </li><li>将外部直流电源（见材料表 ）连接到TEM支架内部的电气馈通，以从TEM室外部向样品施加直流输入信号，以控制电流。电气连接位置取决于TEM支架制造商，但是对于本研究，连接位于支架手柄上，并且销连接器用于将电源从电源施加到TEM样品。通过将输入电流除以横截面积（从图5b中的SEM图像获得）获得在量规部分的标称电流密度。 注意:单次倾斜培训TEM支架包含由单独的位移控制器（材料表 ）控制的内置致动器。 </li><li>在控制机械和电气负载的同时，在以下步骤中获取TEM图像。也可以使用其他应变和电流负载。 </li><li>根据内置的压电致动器的分辨率（在本例中为〜0.34nm），以小的步长逐步施加拉伸应变，直到同时观察到一个或多个位错的运动。这是一个关键的步骤，所以热和/或电能的任何额外的增加产生额外的运动。 </li><li>让样品平衡一分钟。 </li><li>对样品施加输入电流密度。由于横截面积小，即使在大电流密度下，电流应足够低，不会导致显着的温升（ <img alt="方程" src="/files/ftp_upload/55735/55735eq2.jpg" /> ）在t他衡量部分。量规部分中心的最大温升取决于样品几何形状和材料特性，如下所述。 </li><li>为了在稳态条件下对样品进行成像，将其保持在电子束下一分钟，同时在获取图像之前保持电流稳定。允许样品以这种方式平衡应用于机械或电负载的任何改变之后。 </li></ol>

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A., Kamino, T., Michael, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=TEM+sample+preparation+and+FIB-induced+damage.">TEM sample preparation and FIB-induced damage.</a> MRS Bulletin. 32 (5), 400-407 (2007).</li></ol>

作者宣称他们没有竞争的经济利益。

Micro / nanotechnology提供了强大的工具来表征分析室中的材料行为，包括扫描16,18,19,20,21和透射电子显微镜13,22,23,24。这种原位测试能力对材料科学和工程界来说是非常有吸引力的，因为可以使用高分辨率电子显微镜25,26直接观察到基本的微观结构和潜在的变形机制。 在这里，我们提出了一种基于微设备的方法来利用独特的辅助来研究材料样品的耦合电和机械行为原位 TEM的原理。这种方法中的步骤需要使用光刻，反应离子蚀刻设备，电子显微镜的平均经验，以及在这里使用的高质量激光加工系统的访问和训练。虽然采用银环氧树脂和碱性光学显微镜，使用简单的手段来完成标本和硅胶支架的组装，但要注意不要损坏样品计量部分。在处理样品时始终是这样。在铜样品的最终FIB研磨过程中也必须注意。在最终抛光期间减少加速电压（5kV）和电流（&lt;80pA） 27将减少可能的样品损伤28并产生平滑的，无缺陷的量规部分。要记住的另一个重要项目是检查与TEM夹具电隔离的样品，以确保施加的电流通过仪表部分一旦实验开始。 晶片蚀刻工艺包括对于制造EAD样品的良好框架至关重要的一些步骤。将500μm支撑晶片临时粘合到180μm晶片之间，在晶片之间具有均匀的临时粘合剂涂层是重要的，不仅有助于处理脆弱的蚀刻晶片，而且支撑晶片也有利于等离子体蚀刻工艺期间的热传递。传热不足可能导致PR掩模的蚀刻和硅框架的后续非目标蚀刻。定期测量蚀刻沟槽深度也很重要。必须完全蚀刻较薄的顶部硅晶片，但对支撑晶片应进行最小蚀刻，以使其能够作为较薄晶片的均匀散热器。最后，重要的是用丙酮彻底清洁蚀刻的晶圆，然后在SiO 2沉积之前用去离子水冲洗，以最小化任何剩余的重量sidues。 这里显示的EAD实验图像是可以预期的代表，但可以对分辨率，剂量和帧速率进行修改，以允许更好地观察和定量位错。此外，图像处理软件可以用于分析一系列具有增强分辨率的TEM图像。 MEMTS为研究机电材料行为提供了几个独特的优势。该系统能够直接观察在机电负载下控制宏观材料变形的纳米尺度现象。其次，具有小截面的样品计量部分提供了使用低电流大小施加大量电流密度的能力，从而消除了使用高功率仪器所固有的安全问题。例如，将1,000A / mm 2的电流密度施加到1mm 2计量段将仅需要1kA如果量规横截面减小到1μm2，则为1 mA。更重要的是，使用较低的电流有助于热管理。 MEMTS也是独特的，因为其对准和组装不需要昂贵的设备，并且与其他基于微型设备的组装方法相比并不是时间密集的。 这里描述的方法很好地适用于金属，陶瓷和聚合物的机电测试，但它也可用于探索每种材料类别内的微观结构依赖的机电行为。例如，可以通过制备代表性样品来研究单晶和多晶结晶度，晶粒取向，晶粒尺寸，相分布和缺陷密度对机电行为的影响。从这样一个全面的研究中获得的见解可以提供进一步了解EAD驱动机制和提高EAD制造能力所需的理解。说更多的布拉dly，MEMTS可能是研究利用热电耦合的其他设备的有用平台。例如，它可以用于观察热电冷却器中使用的材料，其通过塞贝克效应将施加的电压转换为温度差。 尽管使用本文概述的工艺进行的实验还没有显示出电辅助的变形发生在没有显着的焦耳加热的情况下，需要进一步的实验。这里描述的过程利用了一小组实验条件并集中在局部区域上。需要使用多种材料，电流密度和时间尺度的更全面的一组实验来更确定地验证EAD中是否存在纯粹的电气效应。当前的MEMTS方法的一个技术限制是在原位实验中缺乏量化作用于样品的力的能力。力量是至关重要的以获得应力应变数据（ 例如 ，定量鉴定样品何时达到流动应力），并且当与原位观察结合时，直接提供微观结构性质关系。为了实现这一独特的研究机会，我们正在努力修改Si框架以集成力传感器。

电辅助变形（EAD）是锻造，冲压，挤压等金属变形过程的有用工具。 EAD过程包括在变形期间通过金属工件施加电流，通过减少流动应力，增加应变到失效，有时消除形成1,2,3之后的回弹，显着提高金属成形性。尽管其使用增长，但对于EAD提高金属成形性的机制尚未达成共识。本文介绍了实验的样品制备和测试程序，其中可以分离潜在的竞争性EAD机制，并在测试过程中实现原位显微结构检查。 EAD对金属成形的影响有两个假设。第一个假设，焦耳加热效应，sta所施加的电流在成形金属中遇到电阻，导致温度升高并导致材料软化和膨胀。第二个假设被称为电塑性，其中电流通过降低位错活化能而增加变形。这两个假设都是从20世纪70年代的实验中产生的，涉及应用于机械变形金属4,5的短时电流脉冲。最近的研究通常涉及较低的电流直流脉冲，这与制造应用更相关，但是研究人员在对EAD数据的解释方面仍然不同意。 由于施加的电流的高度耦合性质和增加的热能，解释EAD数据是困难的。高导电性金属中的电流密度即使很小也能显着提高材料的温度; 例如 ，130-240℃，电流密度为33-120A / mm 2 ，用于各种铝和铜合金6,7,8,9 。这种温度变化可以显着影响弹性模量，屈服强度和流动应力，使得区分热和电致塑性效应变得具有挑战性。突出这个困难，可以发现最近的研究支持焦耳加热假说或电塑假说。例如，研究铝，铜和钛的各种合金中的机电变形，研究人员已经报道，电致塑性有助于增强变形，因为这种效果不能仅仅通过焦耳加热来解释1,6,7。与这些报告相反的是研究表明EAD减轻压力钛，不锈钢和Ti-6Al-4V热效应10,11 。 热管理不是EAD研究的具体内容，而是调查机电材料性质时的一般问题。特别是在大型样品中，质心与其周围深度绝缘，保持均匀的温度可能具有挑战性。与样品尺寸相关的另一个机电测试挑战是能够进行与机电应力相关的基本微结构变化的原位和实时观测。常规地在标准试样12上进行原位 TEM机械试验，但是样品的不均匀横截面会在测量段附近产生电流密度和热传递的几何依赖性变化。总而言之，观察和解释EA的主要挑战<html> D机制与样品尺寸有关，可概括如下:1）热偶耦合影响样品温度，使得难以分离单一提出的EAD机制; 2）标准测试样品和程序不存在于原位实时在施加的电流下研究张力材料。通过在透射电子显微镜（TEM）中用超低体积计量部分的样品进行EAD实验，同时控制电流，机械负载和温度，可以克服这些挑战。 在本文中，我们描述了EAD实验的样品制备和测试程序，其中通过使用附着到较大的微/纳米尺度部分（10μm×10μm×100nm）的样品结构使焦耳加热效应可忽略不计稳定支撑框架。通过分析和数值模拟，已经显示出来在这种配置下，甚至高电流密度（〜3,500A / mm 2 ）导致样品温度（&lt;0.02℃）几乎没有增加。基于微器件的机电测试系统的三维示意图（MEMTS） 如图 1所示，这里提出的另一个重要的优点是，不像检查样品那样检查样品，如通常做的那样，样品结构和支撑框架被设计成直接配合到透射电子显微镜TEM）样品架同时具有同时施加电气和机械载荷的能力，该设置可实现原子级分辨率下的材料变形的实时原位观察，尽管单晶铜样品用于本文概述的步骤，该方法具有足够的柔性以适用于其他材料试样ing金属，陶瓷和聚合物15,16 。

<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>Silicon wafers</td>
			<td></td>
			<td></td>
			<td>Any high-quality polished wafers of the correct thickness will work</td>
		</tr>
		<tr>
			<td>Photoresist</td>
			<td>Dow</td>
			<td>SR220-7</td>
			<td></td>
		</tr>
		<tr>
			<td>Photoresist developer</td>
			<td>Shipley</td>
			<td>MF 24A</td>
			<td></td>
		</tr>
		<tr>
			<td>Photoresist developer</td>
			<td>Rohm and Haas</td>
			<td>MF 319</td>
			<td></td>
		</tr>
		<tr>
			<td>Temporary wafer adhesive</td>
			<td></td>
			<td>Crystalbond 509</td>
			<td>Available from a variety of sources</td>
		</tr>
		<tr>
			<td>Iductively Coupled Plasma Reactive Ion Etching (CP-RIE) system</td>
			<td>Oxford</td>
			<td>Plasmalab system 100 ICP RIE</td>
			<td></td>
		</tr>
		<tr>
			<td>Profilometer</td>
			<td>Veeco</td>
			<td>Dektak 150</td>
			<td></td>
		</tr>
		<tr>
			<td>Plasma-Enhanced Chemical Vapor Deposition (PECVD) system</td>
			<td>Oxford</td>
			<td>Plasmalab system 100 PECVD</td>
			<td></td>
		</tr>
		<tr>
			<td>Thin specimen sheet</td>
			<td>Surepure Chemetals</td>
			<td>3702, 3703, 3704 or 2236</td>
			<td>13 &#181;m and 25 &#181;m-thick copper, 99.99% 4N Pure</td>
		</tr>
		<tr>
			<td>Photoresist</td>
			<td>Shipley</td>
			<td>1818</td>
			<td></td>
		</tr>
		<tr>
			<td>355 nm, 10 W, solid-state, frequency tripled Nd:YVO4 pulsed laser</td>
			<td>JDSU</td>
			<td>Q301-HD</td>
			<td></td>
		</tr>
		<tr>
			<td>Liquid ferric chloride</td>
			<td>Sigma-Aldrich</td>
			<td>157740</td>
			<td></td>
		</tr>
		<tr>
			<td>Conductive silver epoxy</td>
			<td>Chemtronics</td>
			<td>CW2400</td>
			<td></td>
		</tr>
		<tr>
			<td>Silver wires</td>
			<td></td>
			<td></td>
			<td>Any highly conductive metallic wires will work (&#60;100 &#181;m in diameter)</td>
		</tr>
		<tr>
			<td>Focused Ion Beam (FIB)</td>
			<td>FEI</td>
			<td>Nova 600</td>
			<td></td>
		</tr>
		<tr>
			<td>Single tilt straining TEM holder</td>
			<td>Gatan</td>
			<td>654</td>
			<td></td>
		</tr>
		<tr>
			<td>Displacement controller</td>
			<td>Gatan</td>
			<td>902 Accutroller</td>
			<td>May be sold with the TEM holder</td>
		</tr>
		<tr>
			<td>CO2 laser cutter</td>
			<td>Universal Laser Systems</td>
			<td>VLS 3.50</td>
			<td>Use 50% power and 15% speed</td>
		</tr>
		<tr>
			<td>Electrical insulation sheet</td>
			<td></td>
			<td>0.5 mm-thick Hard Fiber Electrical Grade Sheet (Fishpaper)</td>
			<td>Available from a variety of sources</td>
		</tr>
		<tr>
			<td>Transmission Electron Microscope (TEM)</td>
			<td>FEI</td>
			<td>Tecnai G2</td>
			<td></td>
		</tr>
		<tr>
			<td>External power supply</td>
			<td>Keithley</td>
			<td>2400 SourceMeter</td>
			<td></td>
		</tr>
	</tbody>
</table>

a novel method for in situ electromechanical characterization of nanoscale specimens

电子辅助变形（EAD）越来越多地被用于提高金属在诸如钣金轧制和锻造的过程中的成形性。尽管对负责EAD的潜在机制有不同意见，仍采用这种技术。与先前的EAD研究相比，本文所述的实验程序能够进行更明确的研究，通过消除导致以前EAD结果的不一致的热效应。此外，由于这里描述的方法使得能够在透射电子显微镜（TEM）中实时地进行EAD观察，所以它优于现有的在测试后观察EAD效应的验尸方法。测试样品由使用激光和离子束研磨的组合制造的具有纳米级厚度的独立拉伸试验部分的单晶铜（SCC）箔组成。 SCC安装到提供给我的蚀刻硅基底板上机电支持和电气隔离，同时用作散热器。即使在高电流密度（〜3,500 A / mm 2 ）下，使用这种几何形状，测试部分的温度升高可以忽略不计（&lt;0.02°C），从而消除了焦耳加热效应。通过获取和分析一系列TEM图像来实现材料变形监测和识别对微观结构（ 如位错）的相应变化。我们的样品制备和原位实验程序是坚固的和通用的，因为它们可以容易地用于测试具有不同微结构的材料， 例如单晶和多晶铜。

如上所述的准备和测试应该导致样品在其规格上断裂，类似于图 6a所示的单晶铜（SCC）样品。机械故障应伴随着电阻的大幅度增加，证实SCC试样通过绝缘垫圈和氧化物涂覆的硅框架电隔离。应使用聚焦在区域轴附近的TEM的亮场模式观察样品中的平面位错。通过逐渐增加应变直到达到流动应力（后期平衡状态），位错运动应该是可见的（ 图 6b）。随着额外的应变和/或施加的电流，可以连续监测相应的位错运动。 数字图7示出了在SCC标本13的EAD实验期间的代表性图像。在将样品拉伸至其后产量平衡状态之后，施加额外的应变而不施加任何电流（参见图 7b）。这导致了新的位错回路（或可能的第二位错滑行）， 如图 7 b 2中的箭头所示 。不改变应变，然后施加500A / mm 2的电流密度，但是在任何位错中都不会产生明显的运动（ 图 7b）。将电流除去，将样品保持恒定1分钟，再次增加菌株，再次产生由图 7b中箭头所示的位错回路的显着变化</st荣&gt; 4 。该结果说明了该过程隔离电辅助变形中涉及的热和电效应的潜力。还使用这种技术进行了涉及更高电流密度（高达5kA / mm 2 ）的实验，产生类似的结果 - 在没有额外的应变的情况下，没有观察到的额外位错运动。使用更高的电流密度强调了这种技术去除焦耳加热引起的热应力的能力，这些复杂的以前的EAD数据集是复杂的。 考虑到样品规格尺寸小，选择高品质材料至关重要。例如，在规格部分附近的微观材料缺陷（ 例如空隙）将导致样品在材料制备过程中的灾难性故障（ 图 4g ）。这是特别的<html>具有挑战性，因为难以知道量规部分中是否存在看不见的材料缺陷，而不进行附加的非破坏性测试，例如X射线衍射形貌。 激光或聚焦离子研磨期间的另一个关键挑战是可能的表面损伤，包括Ga离子注入，离子束诱导位错以及激光诱导加热形成非晶结构。通过使用温和的FIB研磨工艺可以除去大部分的表面伪影（步骤3.3）。然而，使用这种微细加工技术仍然需要仔细考虑，因为这些表面缺陷可能改变样品的微结构并且极大地影响EAD实验结果。在我们的工作中，我们利用高分辨率的TEM图像和衍射图来证实我们的样品确实是原始的单晶铜图 6 c 。 内容"fo:keep-together.within-page ="1"&gt;值得注意的是，仪表部分中心的最大温升可以使用以下公式计算13 : <img alt="方程" src="/files/ftp_upload/55735/55735eq3.jpg" />哪里<img alt="方程" src="/files/ftp_upload/55735/55735eq4.jpg" />是目前的密度， <img alt="方程" src="/files/ftp_upload/55735/55735eq5.jpg" />是仪表长度， <img alt="方程" src="/files/ftp_upload/55735/55735eq6.jpg" />是电阻率， <img alt="方程" src="/files/ftp_upload/55735/55735eq7.jpg" />是热导率。该方程式表明，仪表部分的温度升高对于非常敏感<img alt="方程" src="/files/ftp_upload/55735/55735eq8.jpg" />因为最大试样温度升高与量规长度的平方直接相关。例如，将测量段长度增加一个数量级，从10μ<html> m（在本研究中使用）至100μm，会使温度升高两个数量级。而不是温度上升约0.02°C，温度会升高约2°C，这可能在本研究中有显着差异。此外，材料选择也会影响温升。在本研究中使用的铜具有相对低的电阻和高导热系数，因此，对于给定的电流密度，铜样品中的预期温度升高将比其他材料样品小得多。作为示例，与铜相比，铂具有6倍大的电阻率和5倍的电导率17 ，因此，当铂长度和给定的电流密度是铂时，铂壳的温度上升（约30倍）将大大增加相同。 / p&gt; &lt;/ p&gt; 图1:基于微型设备的机电测试系统（MEMTS）。该图像是三维（3D）原理图，显示了重要组件以及样本如何与TEM支架相配合。没有显示将样品连接到TEM支架上的针的线。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig1large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图2" src="/files/ftp_upload/55735/55735fig2.jpg" /> 图2:硅框架制造工艺。裸光子晶片（ a ）被光刻胶（ b ）旋涂，然后使用光刻将其图案化。暴露的光致抗蚀剂被开发出以暴露下面的Si晶片（ c ）。晶片临时结合到较厚的支撑晶片上并具有反应性离子蚀刻（RIE）用于蚀刻通过较薄的顶部晶片（ d - e ）。丙酮用于去除光致抗蚀剂并分离支撑晶片（ f ）。然后在蚀刻的晶片（ g ）的所有表面上沉积氧化硅层。最后，通过小心地将它们从支撑片（ h ）中小心地拉出来，将各个框架与晶片分离。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig2large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图3" src="/files/ftp_upload/55735/55735fig3.jpg" /> 图3:金属样品制造。 （ a ）铜样品阵列的光学图像（ b ）单个样品，（ c ）测量仪器部分的放大视图。制造工艺步骤如（ d </strong&gt;），这是（ b ）中A --- A的横截面。激光切割（ d ，顶部）时，薄膜的两面都涂有光致抗蚀剂以保护样品。结构被激光加工（ d ，第二），然后蚀刻以产生平滑的边缘（ d ，第三）。许多标本可以由（ a ）所示的单个制造运行生产。最后，剥离光致抗蚀剂，并从样品片（ d ，底部）中轻轻取出各个样品。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig3large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图4" src="/files/ftp_upload/55735/55735fig4.jpg" /> 图4:聚焦离子束（FIB）研磨图像。图（ a ）示出了附着在Si框架上的样本和特写视图（插图）激光切割后的样品支架。图像（ b ） - （ e ）显示在连续的FIB通过期间，测量仪部分变得越来越薄。每次通过除去较少的材料以改善表面光洁度并减少由于研磨过程而导致的材料性质变化。然而，仪表部分缺陷可能保留（ f ），甚至在施加任何应变之前也可能导致材料故障（ g ）。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig4large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图5" src="/files/ftp_upload/55735/55735fig5.jpg" /> 图5:安装在TEM支架上的样品。 （ a ）和（ b ）显示了TEM保​​持器中的组装样品，使用gen的表面光滑表面的最终尺寸tle FIB铣削。一旦试样接合到Si框架上，并且使用导电环氧树脂（ c ）连接银线，则Si框架中的两个圆形孔用于将试样安装在TEM支架中。非导电垫圈用于使样品与TEM支架绝缘。最后，使用导电环氧树脂将银线连接到TEM支架销。经修改13 ，经AIP出版许可。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig5large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图6" src="/files/ftp_upload/55735/55735fig6.jpg" /> 图6:代表性的单晶铜（SSC）样品。 （ a ）显示了仪表部分故障后测量的部分（ 图 1中的位置A）。 （ b </strong&gt;）是显示平面位错的量规部分的亮场图像。 （ c ）示出了在测量部分处的衍射图。经修改13 ，经AIP出版许可。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig6large.jpg" target="_blank">请点击此处查看此图的较大版本。</a> <img alt="图7" src="/files/ftp_upload/55735/55735fig7.jpg" /> 图7: 原位 EAD实验TEM图像。这些图像显示了对位错运动的机械和电荷负载效应。 （ b1 ） - （ b4 ）示出（ a ）中的区域（ b ）的放大视图。 （ b1 ）显示出产后平衡状态下的样品。 （ b2 ）识别出由超过（（ <strong&gt; b1）。当施加电流时没有观察到变化（ b3 ）。一旦应变再次增加，再次发现进一步的脱位变化（ b4 ）。经AIP出版许可转载13 。 <a href="http://ecsource.jove.com/files/ftp_upload/55735/55735fig7large.jpg" target="_blank">请点击此处查看此图的较大版本。</a>

Watch this Scientific Journal Video about A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens at JoVE.com

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

使用宏观样品，隔离电气和热效应对电辅助变形（EAD）是非常困难的。已经开发了金属样品微观和纳米结构以及定制测试程序，以评估施加的电流对形成的影响，而不会有焦耳加热和这些样品上位错的演变。

一种新的方法<em&gt;原位</em&gt;纳米级样品的机电表征

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

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Research

JoVE Journal

Engineering

A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

9.1K 次观看.  US Naval Research Laboratory. 使用宏观样品，隔离电气和热效应对电辅助变形（EAD）是非常困难的。已经开发了金属样品微观和纳米结构以及定制测试程序，以评估施加的电流对形成的影响，而不会有焦耳加热和这些样品上位错的演变。 

视频: A Novel Method for In Situ Electromechanical Characterization of Nanoscale Specimens

Concurrent Quantitative Conductivity and Mechanical Properties Measurements of Organic Photovoltaic Materials using AFM

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. Thus, understanding of spatial variations in composition as well as electrical properties of OPV materials is of paramount importance for moving PV technology forward.1,2 In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution. Currently, materials properties measurements performed using commercially available AFM-based techniques (PeakForce, conductive AFM) generally provide only qualitative information. The values for resistance as well as Young's modulus measured using our method on the prototypical ITO/PEDOT:PSS/P3HT:PC61BM system correspond well with literature data. The P3HT:PC61BM blend separates onto PC61BM-rich and P3HT-rich domains. Mechanical properties of PC61BM-rich and P3HT-rich domains are different, which allows for domain attribution on the surface of the film. Importantly, combining mechanical and electrical data allows for correlation of the domain structure on the surface of the film with electrical properties variation measured through the thickness of the film.

Organic photovoltaic (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale inhomogeneity of OPV materials affects performance of photovoltaic devices. In this paper, we describe a protocol for quantitative measurements of electrical and mechanical properties of OPV materials with sub-100 nm resolution.

并行定量的导电性和力学性能测试的有机光伏材料利用原子力显微镜

Organic photovoltaic  (OPV) materials are inherently inhomogeneous at the nanometer scale. Nanoscale  inhomogeneity of OPV materials affects performance ...

科研

工程学

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric vehicles.1,2 However, many challenges, such as energy density and battery lifetimes, need to be overcome before this particular battery technology can be widely implemented in such applications.3 This research is challenging, and we outline a method to address these challenges using in situ NPD to probe the crystal structure of electrodes undergoing electrochemical cycling (charge/discharge) in a battery. NPD data help determine the underlying structural mechanism responsible for a range of electrode properties, and this information can direct the development of better electrodes and batteries.
We briefly review six types of battery designs custom-made for NPD experiments and detail the method to construct the &#8216;roll-over&#8217; cell that we have successfully used on the high-intensity NPD instrument, WOMBAT, at the Australian Nuclear Science and Technology Organisation (ANSTO). The design considerations and materials used for cell construction are discussed in conjunction with aspects of the actual in situ NPD experiment and initial directions are presented on how to analyze such complex in situ data.

In Situ Neutron Powder Diffraction Using Custom-made Lithium-ion Batteries

We describe the design and construction of an electrochemical cell for the examination of electrode materials using in situ neutron powder diffraction (NPD). We briefly comment on alternate in situ NPD cell designs and discuss methods for the analysis of the corresponding in situ NPD data produced using this cell.

原位中子衍射用特制的锂离子电池

Li-ion batteries are widely used in portable electronic devices and are considered as promising candidates for higher-energy applications such as electric ...

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.

在分析微流体装置的热测量技术

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

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

检测和钯的回收，从城市矿山黄金和钴金属使用标有纳米货车车轮形的孔隙新型传感器/吸附剂

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

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.

对于新材料的低温磁输运测量先进的实验方法

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

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices have used devices prepared by spin coating, a process that is not amenable to large-scale fabrication. This mismatch in device fabrication makes it difficult to translate quantitative results obtained in the laboratory to the commercial level, making optimization difficult. Using a mini-slot die coater, this mismatch can be resolved by translating the commercial process to the laboratory and characterizing the structure formation in the active layer of the device in real time and in situ as films are coated onto a substrate. The evolution of the morphology was characterized under different conditions, allowing us to propose a mechanism by which the structures form and grow. This mini-slot die coater offers a simple, convenient, material efficient route by which the morphology in the active layer can be optimized under industrially relevant conditions. The goal of this protocol is to show experimental details of how a solar cell device is fabricated using a mini-slot die coater and technical details of running in situ structure characterization using the mini-slot die coater.

Printing Fabrication of Bulk Heterojunction Solar Cells and In Situ Morphology Characterization

Here, we present a protocol to fabricate organic thin film solar cells using a mini-slot die coater and related in-line structure characterizations using synchrotron scattering techniques.

散装异质结太阳能电池的印刷和制作<em&gt;原位</em&gt;形态特征

Polymer-based materials hold promise as low-cost, flexible efficient photovoltaic devices. Most laboratory efforts to achieve high performance devices ...

High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia (YSZ) Scaffolds by In Situ Carbon Templating Xerogels

We demonstrate a method for the high temperature fabrication of porous, nanostructured yttria-stabilized-zirconia (YSZ, 8 mol% yttria - 92 mol% zirconia) scaffolds with tunable specific surface areas up to 80 m2&#183;g-1. An aqueous solution of a zirconium salt, yttrium salt, and glucose is mixed with propylene oxide (PO) to form a gel. The gel is dried under ambient conditions to form a xerogel. The xerogel is pressed into pellets and then sintered in an argon atmosphere. During sintering, a YSZ ceramic phase forms and the organic components decompose, leaving behind amorphous carbon. The carbon formed in situ serves as a hard template, preserving a high surface area YSZ nanomorphology at sintering temperature. The carbon is subsequently removed by oxidation in air at low temperature, resulting in a porous, nanostructured YSZ scaffold. The concentration of the carbon template and the final scaffold surface area can be systematically tuned by varying the glucose concentration in the gel synthesis. The carbon template concentration was quantified using thermogravimetric analysis (TGA), the surface area and pore size distribution was determined by physical adsorption measurements, and the morphology was characterized using scanning electron microscopy (SEM). Phase purity and crystallite size was determined using X-ray diffraction (XRD). This fabrication approach provides a novel, flexible platform for realizing unprecedented scaffold surface areas and nanomorphologies for ceramic-based electrochemical energy conversion applications, e.g. solid oxide fuel cell (SOFC) electrodes.

High Temperature Fabrication of Nanostructured Yttria-Stabilized-Zirconia YSZ Scaffolds by In Situ Carbon Templating Xerogels

A protocol for fabricating porous, nanostructured yttria-stabilized-zirconia (YSZ) scaffolds at temperatures between 1,000 &#176;C and 1,400 &#176;C is presented.

通过纳米氧化钇稳定的二氧化锆（YSZ）的支架的高温加工<em&gt;原位</em&gt;碳模板干凝胶

We demonstrate a method for the high temperature fabrication of porous, nanostructured yttria-stabilized-zirconia (YSZ, 8 mol% yttria - 92 mol% zirconia) ...

High-speed Continuous-wave Stimulated Brillouin Scattering Spectrometer for Material Analysis

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as aqueous solutions and biomaterials, with fast acquisition times. Here, we discuss the assembly and operation of a Brillouin spectrometer that uses stimulated Brillouin scattering (SBS) to measure stimulated Brillouin gain (SBG) spectra of water and lipid emulsion-based tissue-like samples in transmission mode with &lt;10 MHz spectral-resolution and &lt;35 MHz Brillouin-shift measurement precision at &lt;100 ms. The spectrometer consists of two nearly counter-propagating continuous-wave (CW) narrow-linewidth lasers at 780 nm whose frequency detuning is scanned through the material Brillouin shift. By using an ultra-narrowband hot rubidium-85 vapor notch filter and a phase-sensitive detector, the signal-to-noise-ratio of the SBG signal is significantly enhanced compared to that obtained with existing CW-SBS spectrometers. This improvement enables measurement of SBG spectra with up to 100-fold faster acquisition times, thereby facilitating high spectral-resolution and high-precision Brillouin analysis of soft materials at high speed.

We describe the construction of a rapid continuous-wave-stimulated-Brillouin-scattering (CW-SBS) spectrometer. The spectrometer employs single-frequency diode-lasers and an atomic vapor notch-filter to acquire transmission spectra of turbid/non-turbid samples with high spectral-resolution at speeds up to 100-fold faster than those of existing CW-SBS spectrometers. This improvement enables high-speed Brillouin material analysis.

用于材料分析的高速连续波受激布里渊散射光谱仪

Recent years have witnessed a significant increase in the use of spontaneous Brillouin spectrometers for non-contact analysis of soft matter, such as ...

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic glasses (MGs). Despite their amorphous nature, the identification of hyperfine interactions unveils faint structural modifications. For this purpose, we have employed two techniques that utilize nuclear resonance among nuclear levels of a stable 57Fe isotope, namely M&#246;ssbauer spectrometry and nuclear forward scattering (NFS) of synchrotron radiation. The effects of heat treatment upon (Fe2.85Co1)77Mo8Cu1B14 MG are discussed using the results of ex situ and in situ experiments, respectively. As both methods are sensitive to hyperfine interactions, information on structural arrangement as well as on magnetic microstructure is readily available. M&#246;ssbauer spectrometry performed ex situ describes how the structural arrangement and magnetic microstructure appears at room temperature after the annealing under certain conditions (temperature, time), and thus this technique inspects steady states. On the other hand, NFS data are recorded in situ during dynamically changing temperature and NFS examines transient states. The use of both techniques provides complementary information. In general, they can be applied to any suitable system in which it is important to know its steady state but also transient states.

Methods of Ex Situ and In Situ Investigations of Structural Transformations: The Case of Crystallization of Metallic Glasses

Here, we present a protocol to describe ex situ and in situ investigations of structural transformations in metallic glasses. We employed nuclear-based analytical methods which inspect hyperfine interactions. We demonstrate the applicability of M&#246;ssbauer spectrometry and nuclear forward scattering of synchrotron radiation during temperature-driven experiments.

结构转换的原位和原位研究方法: 金属玻璃结晶的实例

We demonstrate the use of two nuclear-based analytical methods that can follow the modifications of microstructural arrangement of iron-based metallic ...

Method Development for Contactless Resonant Cavity Dielectric Spectroscopic Studies of Cellulosic Paper

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of data that can be obtained from an individual sample and renders it difficult to produce statistically relevant data for unique and rare materials. Resonant cavity dielectric spectroscopy is a non-destructive, contactless technique which can simultaneously interrogate both sides of a sheeted material and provide measurements which are suitable for statistical interpretations. This offers analysts the ability to quickly discriminate between sheeted materials based on composition and storage history. In this methodology article, we demonstrate how contactless resonant cavity dielectric spectroscopy may be used to differentiate between paper analytes of varying fiber species compositions, to determine the relative age of the paper, and to detect and quantify the amount of post-consumer waste (PCW) recycled fiber content in manufactured office paper.

A protocol for the non-destructive analysis of the fiber content and relative age of paper.

纤维素纸非接触式共振腔电谱研究的方法研究

The current analytical techniques for characterizing printing and graphic arts substrates are largely ex situ and destructive. This limits the amount of ...

一种新的方法

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