Name: advanced experimental methods for low-temperature magnetotransport measurement of novel materials
Uploaded: 2016-01-21T14:00:00.000+00:00
Duration: 10 min 36 s
Description: Watch this Scientific Journal Video about Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials at JoVE.com

This work is supported by the National Institute of Standards and Technology of the United States Department of Commerce.

1.准备底物<ol><li>得到的4英寸的硅（Si）晶片重掺杂p掺杂Si构成覆盖约300nm 的 SiO 2。该基板结构将允许衬底以用作背栅。 </li><li>使用制图/设计软件，设计出1厘米×具有均匀间隔的功能，如列举的杂交1厘米图案，在x和y方向上作为位置定位器使用在基板上用于传输样品薄片和对准标记电子束光刻（ 图1）。 <ol><li>打开在起草程序的新文件，如AutoCAD。 </li><li>使用折线得出如下标记:相交的2.25微米×12.00微米矩形标注8.25微米×14.25微米数字字符组成I）十字间隔150微米的一处。二）一角形成的全球位置标识符连接30微米的正方形标有16.50×28.50微米数字恰拉cters;三）小15微米×15微米的杂交等距离任何授予了四种位置标识间隔150微米分开。 </li><li>确保所有位置标识符在1cm以内×1厘米极限适合。 </li><li>该文件保存为.GDS文件或保存为另一个文件（如为.dxf）并将其转换为一个.GDS文件。 </li></ol></li><li>开发或顺序从商业来源与上述1厘米×1厘米花纹横过4英寸×4英寸的空间排列的光掩模，以允许一个4英寸Si晶片上的图案的副本的全覆盖。 </li><li>在Si晶片光刻图案化的光刻胶掩模。 <ol><li>附加4英寸晶片卡盘光刻胶微调。确保它有足够的固定。 </li><li>用干净的镊子，将一个硅晶片上的微调夹头。确保在晶片的中心位于卡盘。 </li><li>用塑料吸管，覆盖polydimethylglutarimide为基础的剥离整个晶圆光刻胶（LOR）。 </li><li>旋转的LOR包覆片以4000rpm进行45秒。 </li><li>烘烤LOR中涂覆的晶片在170℃下5分钟。 </li><li>让LOR涂覆晶片凉爽1-2分钟。 </li><li>用干净的镊子，将LOR涂层的硅晶片上的微调夹头。确保在晶片的中心位于卡盘。 </li><li>使用塑料移液管，包括在传统的酚醛正光刻胶设计为60秒烘烤，在115℃，以产生12.3 KA涂覆整个晶片。 </li><li>旋转晶片以5,000rpm进行60秒。 </li><li>烤晶圆在90-110℃下60秒。 </li><li>让晶圆酷1-2分钟。 </li><li>通过将光掩模的掩模对准朝下（朝向晶片）的掩模的图案化的铬和装载双层-光刻胶涂覆的晶片掩模之下准备接触光刻使光致抗蚀剂朝上（朝向掩模）。 </li><li>晶片对准掩模，使得晶片的整体将与排列1厘米构图15; 1厘米模式。 </li><li>暴露在紫外线宽带（350纳米至450纳米）使用I-线（365nm带通滤波器），在100毫焦/厘米2，或20毫瓦/ cm 2的4.8秒的光。 </li><li>曝光后，发展光致抗蚀剂通过浸渍以常规酚醛正性光刻胶兼容显影剂在RT溶液40-60秒轻度和一致的搅动涂覆晶片。 </li><li>以下浸没在显影剂溶液中的浴，冲洗在去离子水中的晶片。 </li><li>使用氮气枪，吹干显影的光刻胶掩模涂覆晶片。 </li></ol></li><li>存款铬/金金属上使用电​​子束蒸发器的光致抗蚀剂掩模涂覆晶片。 <ol><li>发泄电子束蒸发器室。 </li><li>将晶圆面朝下放在样品支架板。 </li><li>打开电子束蒸发器室门。 </li><li>将样品支架板到衬底支架与晶片朝下。 </li><li>检查Cr和Au都属于淀积源。 </li><li>关闭电子束蒸发器腔门和泵室中以至少4×10 -5帕（3×10 -7托）。 </li><li>存50埃的Cr在0.5埃/秒。 </li><li>存750埃Au中的1埃/秒。 </li><li>沉积之后，允许腔室冷却大约20分钟。 </li><li>发泄电子束蒸发器室。 </li><li>除去样品支架板和从板取下晶片。 </li><li>关闭电子束蒸发器室门和泵的腔。 </li></ol></li><li>执行金属升空。 <ol><li>制备丙酮或 N的浴-甲基-2-吡咯烷酮系溶剂足以浸没4英寸晶片。加热溶剂浴至75℃的热板上并保持在此温度。 </li><li>浸入溶剂浴的4英寸晶圆。覆盖浴使得溶剂不蒸发过。 </li><li>让晶片在75坐在溶剂浴°下进行6-24小时。要小心，不要让所​​有的溶剂蒸发掉。 </li><li>持样品只是用一对镊子的溶剂的表面下方和微妙喷洒丙酮从整个晶片以除去解除断金属的表面上的喷射瓶。 </li><li>冲洗的异丙醇浴晶片1-2分钟。 </li><li>冲洗中的去离子水的浴晶片1-2分钟。 </li><li>使用氮气枪，吹干晶片。 </li></ol></li><li>切块的晶片切割成用金刚石划线或切割锯个体样品片。如果一个切割锯时，保护在晶片表面用聚甲基丙烯酸甲酯掩模。 <ol><li>附加4英寸晶片卡盘光刻胶微调。确保它有足够的固定。 </li><li>使用清洁的镊子，将晶片上的离心器卡盘。确保在晶片的中心位于卡盘。 </li><li>使用塑料移液管，覆盖在聚甲基丙烯酸甲酯（PMMA）在整个晶片。 </li><li>旋PMMA包覆晶片在5,000rpm下120秒。 </li><li>烘烤，在180℃下120秒的PMMA包覆晶片。 </li><li>让PMMA包覆晶片凉爽1-2分钟。 </li><li>切块的样品成单独的样品片约为1厘米×1厘米大小。 </li></ol></li><li>从晶片表面去除有机残留物。 <ol><li>制备浴缸的硫酸和过氧化氢为基础的汽提器/有机清洁剂，丙酮的浴，异丙醇浴，和去离子水2浴。 </li><li>让基板片浸泡在丙酮浴中15分钟，搅拌下通过高频超声处理。 </li><li>移动衬底片的异丙醇浴中，让它浸泡由高频超声处理，搅拌15分钟。 </li><li>移动衬底片到一个去离子水浴中，并让其浸泡由高频超声处理，搅拌15分钟。 </li><li>移动衬底片的其他的去离子水浴中，让它浸泡用于通过高频超声处理，搅拌15分钟。 </LI&gt; <li>移动衬底片的硫酸和过氧化氢为基础的汽提器/有机清洗液和让它浸泡60分钟无搅动。 </li><li>同时衬底片是在有机清洗液，适当处理的其他浴的内容并清洗玻璃器皿。准备两个新的去离子水浴场。 </li><li>以下的有机剥离，将基板件中的去离子水浴中，并让它浸泡5分钟，同时搅拌由高频超声处理。 </li><li>移动衬底片的其他的去离子水浴中，让它浸泡5分钟，同时搅拌由高频超声处理。 </li><li>使用氮气枪，吹干衬底片。 </li></ol></li></ol> 2.样品转移到片状基材<ol><li>合成或从合作者或商业源获得高品质的大样。 </li><li>去角质样片。 <ol><li>切几片标准晶片切割的TaPE略微-较大超过1厘米×3厘米，留下剥离纸覆盖粘合剂。 </li><li>用一把锋利的剃刀，小心地取出离型纸的一部分，使略超过1厘米×1cm的胶粘剂是对每件磁带暴露。 </li><li>用力按下一个准备一块胶布对大样的粘接部分。如果大样是由非常小的粉末状的片，倒入少量样品的载玻片上，按磁带插入幻灯片上的积累样本。 </li><li>剥离从散装样品确保上的粘合剂样品的良好覆盖胶带。 </li><li>按样品片胶带的粘合面非常坚决地反对另一块胶带的粘合面。 </li><li>剥离两片带分开，目视检查样本覆盖的两片胶带。 </li><li>重复这个过程，2.2.5和2.2.6，直到样品片出现几乎是透明的。 </li><li>用力将胶带机智的粘合面对一块制备的基板的从第1步剥离胶带远h进样薄片离开附着于基材样品薄片。 </li></ol></li><li>目视搜索使用光学显微镜（图2）适合样品薄片，并注意其在基板利用构图步骤1.2-1.4所述位置标记的位置。 </li><li>用原子力显微镜（AFM）测量样品片的厚度。样品薄片应当在厚度10小于100纳米。 </li><li>存款溅射二氧化硅（可选）。 注意:此步骤是仅必要的，如果范德华力附着的样品与基板不足以足够的附着力。这样做不允许样品的制造成霍尔棒通过在本文中（步骤3.3）所概述的程序。 <ol><li>排气溅镀系统负载锁。 </li><li>打开负载锁的门。 </li><li>将样品容纳件样品转移到片样品架和地点样本支架上的传送臂。 </li><li>关闭负载锁定装置的门和抽气装载锁定。 </li><li>启动序列与样品架传送到溅射室。 </li><li>等待的2.7×10 -5帕（2×10 -7）基地真空。 </li><li>使用DC电源，溅射的 SiO 2的100-200纳米到样品片收容转移样品薄片。 </li><li>沉积之后，启动序列与样品架返回到负载锁定。 </li><li>泄负载锁定并取出样品架。 </li><li>除去从样品保持器的碎片。 </li><li>抽空溅射系统负载锁定。 </li></ol></li><li>准备一摞层状材料的薄片 注意:如果研究人员希望产生脱落，并确定在步骤2.1-2.4多个片组成的异质这一步才是必需的。 <ol><li>通过将一小滴的P创建一个透明的机械邮票olydimethylsiloxane（PDMS）在真空载玻片和固化。 </li><li>旋PDMS上的顶部聚丙烯碳酸酯（PPC）作为印模和层状材料之间的直接接触。 </li><li>定位机械邮票上的异质结构栈中使用的层状材料的第一薄片。 </li><li>按邮票向下样品片。 </li><li>该系统加热到约40℃，以增加PPC和样品片之间的吸引力。 </li><li>慢慢抬起印模与附着到PPC中样品薄片。 </li><li>定位在异质结构堆叠要使用超过层状材料的下一薄片附有样品薄片的机械邮票。 </li><li>确保保持排列的两个样品薄片，缓慢降低戳，使得附连到PPC中薄片进入与层状材料的下一薄片在异质结构栈中使用的接触。 </li><li>轻轻按下印记向下SAMPLË片。 </li><li>该系统加热到约40℃，增加样本片之间的吸引力。 </li><li>慢慢抬起印模与附着在堆叠中的样品薄片。 </li><li>重复步骤2.6.7-2.6.11直至所需结构完成。 </li><li>通过轻轻按压含有层状材料的堆叠到衬底片的邮票的异质结构栈转移到一个新的衬底。 </li><li>加热该体系至100℃。 </li><li>慢慢抬起邮票上，留下连接到衬底片层状材料的薄片的堆叠。 </li></ol></li></ol>器件结构3.电子束曝光<ol><li>使用光学显微镜，采取公聚焦图像在20X放大倍数的样本薄片/片栈将用于设备构图和100X。包括在电子束模式D中的至少一个位置标记图案化步骤1.2-1.4用于对准目的的图像中ESIGN。 </li><li>使用制图/设计软件，设计准备的电子束光刻。 <ol><li>在步骤1.2产生开放式设计文件。 </li><li>进口20X图像从步骤3.1，并相应地调整图像大小与设计适当规模。 </li><li>图像对准在设计的位置标记对应于其中样品薄片位于所述图案化衬底片上。 </li><li>使用100X图像重复步骤3.2.2和3.2.3。 </li><li>创建一个新层的设计方案，绘制出6端子霍尔棒模式在样本图像，使得暴露的区域将被腐蚀掉，留下厅酒吧。 </li><li>创建一个新层的设计方案，电气金属触点从终端领先的样品接触垫。 </li><li>文件保存到一个.GDS文件或将其保存在另一种格式，并转换成一个.GDS文件。 </li></ol></li><li>模式6端子霍尔棒PMMA面罩（跳过这一步，如果SiO 2的</suB&gt;被覆​​层沉积在步骤2.5）。 <ol><li>旋的层聚甲基丙烯酸甲酯具有95万的分子量根据在步骤1.7.1至1.7.6概述的程序配制样品上。 </li><li>装载样品放入电子束光刻系统。 </li><li>利用扫描电子显微镜（SEM），从样品11定位对准标记在衬底上为止。 </li><li>根据具体所使用的电子束光刻系统中的过程校准系统进行适当的阶段转动和长度尺度。 </li><li>关掉电子束，以防止PMMA的无用曝光和中心光束位置在在步骤3.2中制备的图案的中心。 </li><li>加载.GDS文件拖到电子束光刻系统计算机和对系统编程，以从步骤3.2.5具有希望的分辨率，根据特定于所使用的电子束平版印刷系统的打印过程霍尔图案层。 </li><li>执行T他电子束系统的图案化方案，以根据系统的用户手册所述的PMMA暴露于电子束。 </li><li>除去从电子束系统的样品。 </li></ol></li><li>蚀刻样品分成6端子霍尔棒（跳过这一步如果二氧化硅涂层沉积在步骤2.5）。 <ol><li>泄反应离子蚀刻系统。 </li><li>装载样品放入蚀刻室。 </li><li>泵系统，以约1.3×10 -3帕（1×10 -5乇）。 </li><li>利用特有的样品材料以蚀刻样品蚀刻配方。注意:对于的hBN /石墨烯/的hBN栈，从4标准立方厘米（sccm）的O 2和40sccm的CHF 3在60瓦射频产生等离子体（RF）功率具有约30纳米/分钟的蚀刻速率;一个1-2分钟的蚀刻通常是足够的。 </li><li>在蚀刻工艺完成后，泄蚀刻室。 </li><li>卸载样品和泵腐蚀室。 </li><li>冲洗样品在丙酮中为1-2分钟的浴。 </li><li>冲洗的异丙醇浴样品1-2分钟。 </li><li>冲洗中的去离子水的浴样品1-2分钟。 </li></ol></li><li>模式PMMA掩码的金属触点沉积。 <ol><li>旋的层聚甲基丙烯酸甲酯具有495,000的分子量根据在步骤1.7.1至1.7.6概述的程序配制样品上。 </li><li>旋的PMMA配制的950000分子量的第二层到样品上，根据在步骤1.7.1至1.7.6概述的程序。 </li><li>重复步骤3.3.2-3.3.8，这一次从步骤3.2.6利用接触图案层。 </li></ol></li><li>如果SiO 2的覆盖层沉积在步骤2.5中，蚀刻掉的 SiO 2在由掩模露出的区域，以允许电触点直接与样品薄片连接。 <ol><li>硬烤掩模在180℃5分钟。 </li><li>让1-2分钟样品凉爽。 </li><li>蚀刻暴露的 SiO 2，2％的HF浴中足够长的时间，以暴露样品薄片而不损坏PMMA掩模-约1-2分钟为100纳米的 SiO 2，目视确认该蚀刻每10-20秒到进度确保PMMA仍然完好无损。 </li><li>如果PMMA的掩模损坏，除去PMMA通过漂洗丙酮的样品60秒，然后异丙醇60秒，然后用去离子水60秒，吹干使用氮气枪，然后重复步骤3.5的样品。 </li></ol></li><li>存款铬/金金属上使用电​​子束蒸发器，通过重复步骤1.5的样品。 </li><li>重复步骤1.6执行金属升空。 </li></ol> 4.执行磁输运实验<ol><li>坚持样本电气运输系统包被装载到运输系统探头端部与银浆，让干燥的电器准备运输包装已制成的样品。使用线键合机精读NECT薄金线从该装置的接触焊盘到封装接触垫。 </li><li>装载样品放入磁输运系统。 <ol><li>附加包到探针尖端被插入到所述磁输运系统，并确保它被牢固地附着。连接电测量设备（源表，锁定放大器等 ）来探测，并连接到所有三个温度控制通道和电气测量通道。 </li><li>放空气闸，插入探头尖端插入气闸，并锁定到位钳和O形圈。 注意:步骤4.2.3和4.2.4-4.2.6和4.2.8对应必要进行使用氦3探头传输测量步骤。 </li><li>设置minisorb温度在插入到330 K至除去水蒸汽和打开气体交换阀和使用真空泵进行30分钟泵送系统，直到压力低于0.67帕（5×10 -3乇）。 </li><li>关闭交换阀和锁气阀并打开阀门分离从测量空间中的气闸的空间。 </li><li>简要地开放（不超过2秒），并关闭交换阀引入少量氦4气体到探头的空间。 </li><li>设置minisorb温度到25 K和mainsorb温度到40 K。 </li><li>慢慢放下探头插入测量空间，直至样品是场中心。 </li><li>一旦系统已达到200 K，按下控制器软件氦3冷凝序列按钮来实现温度低至0.300 K. </li></ol></li><li>取传输测量在一定温度范围内，磁场，栅极电压等的<ol><li>对于所有的测量，同时保存到数据文件中，由电流源，所述电压纵向（平行于所提供的电流）由电压表测量提供的电流/锁定放大器专用于该测量中，样品的温度由一个温度传感器位于样品附近，和由磁体产生的磁场进行测量。 </li><li>如果霍尔测量需要，节省霍尔电压（横向于所提供的电流）提供到数据文件，并且如果栅极电压被提供给调谐在信道的载流子密度，保存由相应的电压源提供的栅电压，因为好，每个测量在期望的采样率。 注意:采样速率为测量依赖于改变实验参数（温度，场， 电压等）是否被扫（从1开始重视并在设定值与变化的恒定速率结束）或阶梯形（稳定在预定的值）。在前者的情况下，采样率高达基础上，他们希望生成的数据文件的大小的研究者的判断。在后一种情况下，测量是在不断变化的实验参数的稳定。生成和保存DAT一个文件是通过数据采集软件进行处理。 </li></ol></li></ol>

<ol>
	<li>Doty, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+CdZnTe+crystals+grown+by+a+high+pressure+Bridgman+method.">Properties of CdZnTe crystals grown by a high pressure Bridgman method.</a> Journal of Vacuum Science &amp; Technology B. 10 (4), 1418-1422 (1992).</li><li>Ikesue, A., Kinoshita, T., Kamata, K., Yoshida, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+optical+properties+of+high-performance+polycrystalline+Nd-YAG+Ceramics+for+Solid-State+Lasers.">Fabrication and optical properties of high-performance polycrystalline Nd-YAG Ceramics for Solid-State Lasers.</a> Journal of the American Ceramic Society. 78 (4), 1033-1040 (1995).</li><li>Elwell, D., Scheel, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Crystal Growth From High-Temperature Solutions. , (2011).</li><li>Doty, F. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Properties+of+CdZnTe+crystals+grown+by+a+high+pressure+Bridgman+method.">Properties of CdZnTe crystals grown by a high pressure Bridgman method.</a> Journal of Vacuum Science &amp; Technology B. 10 (4), 1418-1422 (1992).</li><li>Ikesue, A., Kinoshita, T., Kamata, K., Yoshida, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fabrication+and+optical+properties+of+high-performance+polycrystalline+Nd-YAG+Ceramics+for+Solid-State+Lasers.">Fabrication and optical properties of high-performance polycrystalline Nd-YAG Ceramics for Solid-State Lasers.</a> Journal of the American Ceramic Society. 78 (4), 1033-1040 (1995).</li><li>Elwell, D., Scheel, H. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Crystal Growth From High-Temperature Solutions. , (2011).</li><li>Therese, G. H. A., Kamath, P. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Electrochemical+Synthesis+of+Metal+Oxides+and+Hydroxides.">Electrochemical Synthesis of Metal Oxides and Hydroxides.</a> Chemistry of Materials. 12, 1195-1294 (2000).</li><li>Capper, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Bulk+Crystal+Growth+-+Methods+and+Materials.">Bulk Crystal Growth - Methods and Materials.</a> Handbook of Electronic and Photonic Materials. , 231-254 (2007).</li><li>Seiler, D. G., Becker, W. M., Roth, L. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inversion-Asymmetry+Splitting+of+the+Conduction+Band+in+GaSb+from+Shubnikov-de+Haas+Measurements.">Inversion-Asymmetry Splitting of the Conduction Band in GaSb from Shubnikov-de Haas Measurements.</a> Physical Review B. 1, 764-775 (1970).</li><li>Greenblatt, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Molybdenum+Oxide+Bronzes+with+Quasi-Low-Dimensional+Properties.">Molybdenum Oxide Bronzes with Quasi-Low-Dimensional Properties.</a> Chemical Reviews. 88, 31-53 (1988).</li><li>Novoselov, K. S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Two-dimensional+gas+of+massless+Dirac+fermions+in+graphene.">Two-dimensional gas of massless Dirac fermions in graphene.</a> Nature. 438, 197-200 (2005).</li><li>Wang, L., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=One-Dimensional+Electrical+Contact+to+a+Two-Dimensional+Metal.">One-Dimensional Electrical Contact to a Two-Dimensional Metal.</a> Science. 342, 614-617 (2013).</li><li>Giessibl, F. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Advances+in+Atomic+Force+Microscopy.">Advances in Atomic Force Microscopy.</a> Reviews of Modern Physics. 75, 949-983 (2003).</li><li>Smith, K. C. A., Oatley, C. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+Scanning+Electron+Microscope+and+its+Fields+of+Applications.">The Scanning Electron Microscope and its Fields of Applications.</a> British Journal of Applied Physics. 6, 391-399 (1955).</li><li>Geim, A. K., Grigorieva, I. V. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Van+der+Waals+heterostructures.">Van der Waals heterostructures.</a> Nature. 499, 419-425 (2013).</li></ol>

The authors declare no competing financial interests. Commercial materials, instruments and equipment are identified in this paper to specify the experimental procedure as completely as possible. In no case does such identification imply a recommendation or endorsement by the National Institute of Standards.

采集高质量大块样品，其特征在于，以确保适当的组成和结构的后，将样品经图案化成为通过剥离样品的薄片中描绘的几何上1厘米×1厘米的片基片的。基板重p掺杂Si构成覆盖约300nm 的 SiO 2是优选的，因为它们增加了实验参数空间通过使背栅的应用。样品必须足够薄 - 少于10纳米 - 以产生足够的场效应调谐在霍尔棒装置的导电沟道的整体的化学势。样品厚度由适当使用标准的晶片切割用胶?...

先进的电子技术的追求材料的平台要求的高通量材料的合成和随后的表征方法。在这种追求兴趣的新型材料，可以产生散装直接反应合成1,2-，电化学生长3,4-，和其他方法5以更快速的方式相比，如分子束外延或更多参与单晶薄膜沉积技术化学气相沉积。测量块状晶体样品的输运性质的常规方法是切割的矩形棱柱形的片段约为1毫米×1毫米×6毫米的尺寸和连接线导致在一个霍尔棒构6的样品。 某些材料构成挑战，其中传统的散装霍尔棒装置的制造方法是不足以产生一个可测量的装置，用于传输样品测量。这可以是导致产生的结晶太小附加引线到，即使是一个功能强大的光学显微镜下，因为所需的样品厚度是1的量级，以只有几个单层，或因为一个目的是衡量一叠层状二维材料与近或亚纳米厚度。第一类包括，例如纳米线和氧化钼的某些制剂铜器7。第二类包括单对极少数的二维材料，例如石墨烯8层 ，TMDS（ 二硫化钼，WTE 2等），和拓扑绝缘体（ 的 Bi 2硒3，铋锑x 1-X 3碲等 ）。第三类包括制备由经由层转移，的hBN-石墨烯的hBN 9的最显着的一个三层堆积层叠的二维材料的各层通过手工装配异质结构。 新型Ë的探索性研究lectronic原材料的需求，足够制造方法上难以测量的样品设备。通常情况下，第一批直接反应或电化学生长合成新材料的产量非常小的单晶微米尺寸级的尺寸。这种样品在历史上被证明极为困难附加金属接触到，因此有必要改善样品生长参数以实现较大的晶体，以方便运输装置制造，呈现的障碍物的新材料的高通量研究。为了使材料的快速表征，器件制造为非常小的样品的方法，已被设计成只要初步批次已经产生允许新材料的表征。这种方法的细微变化是适用于制造使用二维材料，例如石墨烯，的hBN，和TMDS剥离样品，设备以及这种毫安的多层异质结构terials。设备被附着和引线键合到一个包，用于插入一个商业超导磁体，干燥氦气靠近循环低温恒温器磁输运系统。传输测量是在温度下降到0.300 K和磁场高达12吨

<table><tbody><tr><td>Cryogenic Limited 12 T CFMS</td><td>Cryogen Limited</td><td>CFM-12T-H3- IVTI-25</td><td>Magnetotransport system customized with modulated field magnet (step 4)</td></tr><tr><td>7270 DSP Lock-in amplifier</td><td>Signal Recovery</td><td>7270</td><td>lock-in amplifier for source/drain and voltage measurements (step 4)</td></tr><tr><td>GS200 DC Voltage/Current Source</td><td>Yokogawa</td><td>GS200</td><td>Voltage source for gate voltage application (step 4)</td></tr><tr><td>2636B System Sourcemeter</td><td>Keithley</td><td>2636B</td><td>Sourcemeter for source/drain and voltage measurements</td></tr><tr><td>DWL 2000 Laser Pattern Generator</td><td>Heidelberg Instruments</td><td>DWL 2000</td><td>Generate chrome mask for lithography of substrate location/alignment feature pattern (step 1.3)</td></tr><tr><td>Suss MicroTec MA6/BA6 Contact Aligner</td><td>Suss</td><td>MA6</td><td>Used for the lithography of substrate location/alignment feature pattern (step 1.4.12)</td></tr><tr><td>JEOL Direct Write Electron Beam Lithography System</td><td>JEOL</td><td>JBX 6300-FS&amp;nbsp;</td><td>Perform high-resolution lithography of devices</td></tr><tr><td>Discovery 550 Sputtering System</td><td>Denton Vacuum</td><td>Discovery 550</td><td>Perform SiO&lt;sub&gt;2&lt;/sub&gt; sputtering (step 2.5)</td></tr><tr><td>Infinity 22 Electron Beam Evaporator</td><td>Denton Vacuum</td><td>Infinty 22</td><td>Perform Cr/Au deposition (steps 1.5 and 3.7)</td></tr><tr><td>Unaxis 790 Reactive Ion Etcher</td><td>Unaxis</td><td>Unaxis 790</td><td>Etch sample into Hall bar structure (step 3.4)</td></tr><tr><td>PMMA 495 A4</td><td>MicroChem</td><td>PMMA 495 A4</td><td>Polymer coating/electron beam mask for lithography (step 3.5.1)</td></tr><tr><td>PMMA 950 A4</td><td>MicroChem</td><td>PMMA 950 A4</td><td>Polymer coating/electron beam mask for sample dicing and lithography (steps 1.7.3, 3.3.1, and 3.5.2)</td></tr><tr><td>S1813 positive photoresist</td><td>MicroChem</td><td>S1813 G2</td><td>Positive photoresist (step 1.4.8)</td></tr><tr><td>LOR resist</td><td>MicroChem</td><td>LOR 3A</td><td>Lift off resist (step 1.4.3)</td></tr><tr><td>1:3 MIBK:IPA PMMA developer</td><td>MicroChem</td><td>1:3 MIBK:IPA</td><td>PMMA developer</td></tr><tr><td>MF-321 Developer</td><td>MicroChem</td><td>MF-321</td><td>Novolac positive photoresist-compatible developer solution (step 1.4.15)</td></tr><tr><td>Diglycidiyl ether-terminated polydimethylsiloxane</td><td>Sigma Aldrich</td><td>SA 480282</td><td>For layered material stacking (step 2.6.1)</td></tr><tr><td>Polypropylene carbonate</td><td>Sigma Aldrich</td><td>SA 389021</td><td>For layered material stacking (step 2.6.2)</td></tr></tbody></table>

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.

图3示出了图案化的低温磁输运实验的目的典型霍尔棒装置。在上图的光学图像显示了一个成功制造的石墨烯/的hBN馆吧;下部图显示的过程中出现的Landau能级（LLS）的兰道尔-Büttiker边缘状态的装置的原理图，其可用于计算量化的霍尔电阻的值的传输机制，实验调查，其中将作为要讨论一个典型应用实验方法在本文中详细介绍的。通常情况下，霍尔棒结构的制造...

Watch this Scientific Journal Video about Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials at JoVE.com

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

对于新材料的低温磁输运测量先进的实验方法

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 ...

advanced-experimental-methods-for-low-temperature-magnetotransport

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

10.5K 次观看.  National Institute of Standards and Technology. 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.

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

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 ...

科研

工程学

Sputter Growth and Characterization of Metamagnetic B2-ordered FeRh Epilayers

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using sputtering techniques. Here we describe a method for preparing epitaxial thin films of B2-ordered FeRh by sputter deposition onto single crystal MgO substrates. Deposition at a slow rate onto a heated substrate allows time for the adatoms to both settle into a lattice with a well-defined epitaxial relationship with the substrate and also to find their proper places in the Fe and Rh sublattices of the B2 structure. The structure is conveniently characterized with X-ray reflectometry and diffraction and can be visualised directly using transmission electron micrograph cross-sections. B2-ordered FeRh exhibits an unusual metamagnetic phase transition: the ground state is antiferromagnetic but the alloy transforms into a ferromagnet on heating with a typical transition temperature of about 380 K. This is accompanied by a 1% volume expansion of the unit cell: isotropic in bulk, but laterally clamped in an epilayer. The presence of the antiferromagnetic ground state and the associated first order phase transition is very sensitive to the correct equiatomic stoichiometry and proper B2 ordering, and so is a convenient means to demonstrate the quality of the layers that can be deposited with this approach. We also give some examples of the various techniques by which the change in phase can be detected.

A method to prepare epitaxial layers of ordered alloys by sputtering is described. The B2-ordered FeRh compound is used as an example, as it displays a metamagnetic transition that depends sensitively on the degree of chemical order and the exact composition of the alloy.

变磁B2有序化的FeRh外延层溅射生​​长和表征

Chemically ordered alloys are useful in a variety of magnetic nanotechnologies. They are most conveniently prepared at an industrial scale using ...

Writing and Low-Temperature Characterization of Oxide Nanostructures

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions. Oxide interfaces exhibit a wide range of properties that can be controlled include conduction, piezoelectric behavior, ferromagnetism, superconductivity and nonlinear optical properties. Recently, methods for controlling these properties at extreme nanoscale dimensions have been discovered and developed. Here are described explicit step-by-step procedures for creating LaAlO3/SrTiO3 nanostructures using a reversible conductive atomic force microscopy technique. The processing steps for creating electrical contacts to the LaAlO3/SrTiO3 interface are first described. Conductive nanostructures are created by applying voltages to a conductive atomic force microscope tip and locally switching the LaAlO3/SrTiO3 interface to a conductive state. A versatile nanolithography toolkit has been developed expressly for the purpose of controlling the atomic force microscope (AFM) tip path and voltage. Then, these nanostructures are placed in a cryostat and transport measurements are performed. The procedures described here should be useful to others wishing to conduct research in oxide nanoelectronics.

Oxide nanostructures provide new opportunities for science and technology. The interfacial conductivity between LaAlO3 and SrTiO3 can be controlled with near-atomic precision using a conductive atomic force microscopy technique. The protocol for creating and measuring conductive nanostructures at LaAlO3/SrTiO3 interfaces is demonstrated.

写作和氧化物纳米结构的低温特性

Oxide nanoelectronics is a rapidly growing field which seeks to develop novel materials with multifunctional behavior at nanoscale dimensions.  Oxide ...

Chemical Vapor Deposition of an Organic Magnet, Vanadium Tetracyanoethylene

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in traditional materials, including low cost and mechanical flexibility. In a similar vein, it would be advantageous to expand the use of organics into high frequency electronics and spin-based electronics. This work presents a synthetic process for the growth of thin films of the room temperature organic ferrimagnet, vanadium tetracyanoethylene (V[TCNE]x, x~2) by low temperature chemical vapor deposition (CVD). The thin film is grown at &#60;60 &#176;C, and can accommodate a wide variety of substrates including, but not limited to, silicon, glass, Teflon and flexible substrates. The conformal deposition is conducive to pre-patterned and three-dimensional structures as well. Additionally this technique can yield films with thicknesses ranging from 30 nm to several microns. Recent progress in optimization of film growth creates a film whose qualities, such as higher Curie temperature (600 K), improved magnetic homogeneity, and narrow ferromagnetic resonance line-width (1.5 G) show promise for a variety of applications in spintronics and microwave electronics.

We present the synthesis of the organic-based ferrimagnet vanadium tetracyanoethylene (V[TCNE]x, x~2) via low temperature chemical vapor deposition (CVD). This optimized recipe yields an increase in Curie temperature from 400 K to over 600 K and a dramatic improvement in magnetic resonance properties.

化学气相沉积的有机磁体，钒四氰

Recent progress in the field of organic materials has yielded devices such as organic light emitting diodes (OLEDs) which have advantages not found in ...

化学

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new techniques capable of characterizing their dynamics. Investigating single dopants requires sub-nanometer spatial resolution, which motivates the use of scanning tunneling microscopy (STM). However, conventional STM is limited to millisecond temporal resolution. Several methods have been developed to overcome this shortcoming, including all-electronic time-resolved STM, which is used in this study to examine dopant dynamics in silicon with nanosecond resolution. The methods presented here are widely accessible and allow for local measurement of a wide variety of dynamics at the atomic scale. A novel time-resolved scanning tunneling spectroscopy technique is presented and used to efficiently search for dynamics.

We demonstrate an all-electronic method to observe nanosecond-resolved charge dynamics of dopant atoms in silicon with a scanning tunneling microscope.

全电子纳秒分辨扫描隧道显微镜: 促进单一掺杂剂电荷动力学的研究

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new ...

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 ...

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental techniques and methodologies. Here we use a novel home-built uniaxial-strain device integrated into our variable temperature scanning tunneling microscope that enables us to controllably manipulate in-plane uniaxial strain in samples and probe their electronic response at the atomic scale. Using scanning tunneling microscopy (STM) with spin-polarization techniques, we visualize antiferromagnetic (AFM) domains and their atomic structure in Fe1+yTe samples, the parent compound of iron-based superconductors, and demonstrate how these domains respond to applied uniaxial strain. We observe the bidirectional AFM domains in the unstrained sample, with an average domain size of ~50-150 nm, to transition into a single unidirectional domain under applied uniaxial strain. The findings presented here open a new direction to utilize a valuable tuning parameter in STM, as well as other spectroscopic techniques, both for tuning the electronic properties as for inducing symmetry breaking in quantum material systems.

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Using uniaxial strain combined with spin-polarized scanning tunneling microscopy, we visualize and manipulate the antiferromagnetic domain structure of Fe1+yTe, the parent compound of iron-based superconductors.

利用自旋偏振扫描隧道显微镜对 fe 1+yTe 中的反铁磁领域进行单轴应变操作

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental ...

Magnetic Field Mapping using Off-Axis Electron Holography in the Transmission Electron Microscope

Off-axis electron holography is a powerful technique that involves the formation of an interference pattern in a transmission electron microscope (TEM) by overlapping two parts of an electron wave, one of which has passed through a region of interest on a specimen and the other is a reference wave. The resulting off-axis electron hologram can be analyzed digitally to recover the phase difference between the two parts of the electron wave, which can then be interpreted to provide quantitative information about local variations in electrostatic potential and magnetic induction within and around the specimen. Off-axis electron holograms can be recorded while a specimen is subjected to external stimuli such as elevated or reduced temperature, voltage, or light. The protocol that is presented here describes the practical steps that are required to record, analyze, and interpret off-axis electron holograms, with a primary focus on the measurement of magnetic fields within and around nanoscale materials and devices. Presented here are the steps involved in the recording, analysis, and processing of off-axis electron holograms, as well as the reconstruction and interpretation of phase images and visualization of the results. Also discussed are the need for optimization of the specimen geometry, the electron optical configuration of the microscope, and the electron hologram acquisition parameters, as well as the need for the use of information from multiple holograms to extract the desired magnetic contributions from the recorded signal. The steps are illustrated through a study of specimens of B20-type FeGe, which contain magnetic skyrmions and were prepared with focused ion beams (FIBs). Prospects for the future development of the technique are discussed.

Guidelines are presented for recording and interpreting off-axis electron holograms to provide quantitative images of magnetic fields in nanoscale materials and devices in the transmission electron microscope.

Off-axis electron holography is a powerful technique that involves the formation of an interference pattern in a transmission electron microscope (TEM) by ...

Optimizing Magnetic Force Microscopy Resolution and Sensitivity to Visualize Nanoscale Magnetic Domains

Magnetic force microscopy (MFM) enables mapping local magnetic fields across a sample surface with nanoscale resolution. To perform MFM, an atomic force microscopy (AFM) probe whose tip has been magnetized vertically (i.e., perpendicular to the probe cantilever) is oscillated at a fixed height above the sample surface. The resultant shifts in the oscillation phase or frequency, which are proportional to the magnitude and sign of the vertical magnetic force gradient at each pixel location, are then tracked and mapped. Although the spatial resolution and sensitivity of the technique increases with decreasing lift height above the surface, this seemingly straightforward path to improved MFM images is complicated by considerations such as minimizing topographical artifacts due to shorter range van der Waals forces, increasing the oscillation amplitude to further improve sensitivity, and the presence of surface contaminants (in particular water due to humidity under ambient conditions). In addition, due to the orientation of the probe's magnetic dipole moment, MFM is intrinsically more sensitive to samples with an out-of-plane magnetization vector. Here, high-resolution topographical and magnetic phase images of single and bicomponent nanomagnet artificial spin-ice (ASI) arrays obtained in an inert (argon) atmosphere glovebox with &lt;0.1 ppm O2 and H2O are reported. Optimization of lift height and drive amplitude for high resolution and sensitivity while simultaneously avoiding the introduction of topographical artifacts is discussed, and detection of the stray magnetic fields emanating from either end of the nanoscale bar magnets (~250 nm long and &lt;100 nm wide) aligned in the plane of the ASI sample surface is shown. Likewise, using the example of a Ni-Mn-Ga magnetic shape memory alloy (MSMA), MFM is demonstrated in an inert atmosphere with magnetic phase sensitivity capable of resolving a series of adjacent magnetic domains each ~200 nm wide.

Magnetic force microscopy (MFM) employs a vertically magnetized atomic force microscopy probe to measure sample topography and local magnetic field strength with nanoscale resolution. Optimizing MFM spatial resolution and sensitivity requires balancing decreasing lift height against increasing drive (oscillation) amplitude, and benefits from operating in an inert atmosphere glovebox.

优化磁力显微镜分辨率和灵敏度，以可视化纳米级磁畴

Magnetic force microscopy (MFM) enables mapping local magnetic fields across a sample surface with nanoscale resolution. To perform MFM, an atomic force ...

氧化还原活性 MOF 固态电化学的磁力表征

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.

作者聚焦：氧化还原活性金属有机框架固态电化学中中间体的磁力表征  

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).

氧化还原-活性金属-有机骨架固态电化学中中间体的磁力表征

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

对于新材料的低温磁输运测量先进的实验方法

摘要

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在极低的温度下角分辨光电子能谱

变磁B2有序化的FeRh外延层溅射生长和表征

写作和氧化物纳米结构的低温特性

化学气相沉积的有机磁体，钒四氰

全电子纳秒分辨扫描隧道显微镜: 促进单一掺杂剂电荷动力学的研究

结构转换的原位和原位研究方法: 金属玻璃结晶的实例

利用自旋偏振扫描隧道显微镜对 fe 1₊_yTe 中的反铁磁领域进行单轴应变操作

Magnetic Field Mapping using Off-Axis Electron Holography in the Transmission Electron Microscope

优化磁力显微镜分辨率和灵敏度，以可视化纳米级磁畴

氧化还原-活性金属-有机骨架固态电化学中中间体的磁力表征

对于新材料的低温磁输运测量先进的实验方法

摘要

探索更多视频

此视频中的章节

在极低的温度下角分辨光电子能谱

变磁B2有序化的FeRh外延层溅射生​​长和表征

写作和氧化物纳米结构的低温特性

化学气相沉积的有机磁体，钒四氰

全电子纳秒分辨扫描隧道显微镜: 促进单一掺杂剂电荷动力学的研究

结构转换的原位和原位研究方法: 金属玻璃结晶的实例

利用自旋偏振扫描隧道显微镜对 fe 1+yTe 中的反铁磁领域进行单轴应变操作

Magnetic Field Mapping using Off-Axis Electron Holography in the Transmission Electron Microscope

优化磁力显微镜分辨率和灵敏度，以可视化纳米级磁畴

氧化还原-活性金属-有机骨架固态电化学中中间体的磁力表征

变磁B2有序化的FeRh外延层溅射生长和表征

利用自旋偏振扫描隧道显微镜对 fe 1₊_yTe 中的反铁磁领域进行单轴应变操作