我们感谢 Takanishi 教授在我们实验中的帮助。我们还感谢 DIC 公司提供了这里所研究的化合物。这项工作得到了 jsp 研究员 (16J02711)、jsp KAKENHI 赠款号17H01143 的资助, 以及领导研究生院 "交互式材料军校学生计划" 的资助。

1. 液晶细胞的制备及细胞间隙的测定
<ol><li>
液晶电池的制备
	<ol>
<li>将镀铟/锡氧化物 (ITO) 的玻璃基体切割成所需尺寸 (典型尺寸:10 x 10 x 1.1 毫米,图 2A)。要切割基板, 请用玻璃切割机在他们的脸上划上一条线, 手动切断多余的玻璃。</li>
		<li>用35赫的超声波浴中的洗涤剂清洗切割玻璃基板30分钟. 在超声波浴中用去离子水冲洗10分钟. 更换去离子水并冲洗衬底5次以去除污染物 (图 2B)。用空气除尘器把剩余的水吹掉, 小心不要碰到最宽的底面。</li>
		<li>滴灌聚酰亚胺溶液 (对齐层刨床在材料表) 上的 ITO 涂层一侧的洗涤基质, 并纺大衣的解决方案在 5000 rpm 三十年代 (图 2C)。将基材烘烤200摄氏度, 1 小时, 去除溶剂, 固化聚酰亚胺薄膜。</li>
		<li>把基板放在一个XZ的舞台上, 使基体表面的 ITO 和聚酰亚胺涂层面朝上。将衬底放在用天鹅绒布覆盖的滚筒下, 用空气吸痰固定衬底 (图 2D)。通过调整舞台的高度, 对基板施加均匀和软压力。 注: 在这里, XZ 阶段是由大阪大学的一个机器商店。</li>
		<li>旋转滚筒, 沿水平方向来回移动舞台5次, 用天鹅绒布擦衬底。在 10-50 毫升的玻璃容器中, 将所摩擦的基体蘸上异丙醇, 以去除污染物, 并在80摄氏度内将其干燥几分钟。</li>
		<li>将两个衬底与12微米厚度平板树脂薄膜粘合在一起。注意, 粘接点只放在基体的边缘, 胶合基体的内侧涂上 ITO 和聚酰亚胺。确保相反的基板被摩擦反并联和轻微转移 (约2毫米), 以提供足够的空间, 在两个基板上的电气端子 (图 2E)。</li>
		<li>使用银导电膏将导电导线粘附在上述空间的端子上 (图 2F)。用导电导线在150摄氏度烘烤基板, 1 小时, 以去除银导电膏中的溶剂。</li>
	</ol>
</li>
	<li>
细胞间隙的测定19<ol>
<li>照射在1.1.7 中制备的空白细胞, 白色光传播正常到其最宽的面。用光学光谱仪测量透射光谱, 观察伪正弦振荡 (图 3), 这是由于法-Pérot 效应20而出现的。</li>
		<li>使用关系估计细胞间隙d = λ1λ2/2 (λ2-λ1), 波长λ1和λ 2表示传输谱中的一对相邻峰值波长。</li>
	</ol>
</li>
</ol>2. 液晶混合物的制备及在细胞中的引入
<ol><li>混合两个化合物, 5-辛-2-(4-octyloxyphenyl) 嘧啶 (复合1:图 4A) 和 (S)-5-癸基-2-[4 (2-fluorodecyloxy) 苯基] 嘧啶 (复合2:图 4B) 与质量比率3:1 在玻璃瓶。共制备100毫克溶液 (75 毫克化合物1和25毫克化合物2)。</li>
	<li>把准备好的空白细胞从台阶1.1.7 在一个热的阶段, 保持温度在80°c, 温度在其中混合物从2.1 在各向同性的液体阶段 (图 5)。使用刮刀和毛细管动作将步骤2.1 中的混合物引入细胞中。保持80摄氏度的细胞温度为30分钟, 然后冷却到室温的速率约5°c/分钟。</li>
</ol>3. 样品表征
<ol><li>放置一个细胞填充与混合物从步骤2.2 在一个热点阶段之间的两个交叉偏振片, 并照射它与光。使用显微镜观察混合物的质地, 温度从室温变到80°c, 速度为5摄氏度/分钟, 并通过一个短通滤波器, 调整范围为 ~ 600 nm, 以提高能见度, 如有必要), 并确定液晶相偏振显微照片21 (图 6)。</li>
	<li>从观测到的纹理确定相变序列和过渡温度 (图 5)。对于 SmC * 阶段, 估计螺旋间距为双条纹宽度。</li>
	<li>用差分热分析法确定2.1 型混合料的一阶相变温度 (DTA; 参见材料表和制造商说明), 在一阶阶段提供峰值 (或倾角) 异常转换 (图 7)。</li>
</ol>4. 介质和磁电测量
<ol><li>准备一个商用超导磁体 (见材料表), 配备温度控制器 (2-400 K) 和磁场 (最多9吨)。</li>
	<li>为超导磁体准备一个自制的插入件, 它由三主要部件组成: 样品空间, 一杆包括四同轴电缆和一个连接器端子 (图 8A)。</li>
	<li>将在2.2 中准备好的单元格粘附在插入的样本空间上 (图 8B)。通过焊接将电池的两条导电导线连接到样品空间的端子 (高和低)。确保单元格方向, 以便在与单元格的基板平行的方向上应用磁场。将温度计放在细胞最宽的平面上, 以便准确测量样品温度, 并将插入物引入超导磁体。</li>
	<li>将接头终端连接到LCR表 (参见材料表), 并使用同轴电缆。用LCR计 (参见制造商的说明和我们以前的工作16), 以四的终端方法测量电介质常数作为温度和磁场的函数。</li>
	<li>用同轴电缆将接头端子连接到静电计 (见材料表)。在扫磁场和温度恒定的情况下, 测量与静电计的位移电流的磁场和温度依赖性 (扫磁场的 1.0 T/分钟, 扫入温度的 5 K/分钟; 请参阅制造商的说明和我们以前的工作16)。通过将位移电流作为时间函数来获得电极化。</li>
</ol>

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作者没有什么可透露的。

实验结果表明, 本文所描述的方法成功地证明了液晶中的偶联。在固定的 smectic 层结构中, 观察到的我和磁介电效应可以与分子取向的取向转移有关。然而, 层状结构中的层法线方向n0也可以通过磁各向异性施加磁场来改变。这是因为分子倾向于通过它们的磁性各向异性来进行n和磁场的平行排列。n0和磁场的平行布置也比 SmC...

磁电 (i.) 效应的研究, 电磁 (电) 磁场诱导极化 (磁化), 一直致力于新型的应用, 如传感器和存储技术。最近对我的研究 multiferroics1,2,3,4, 我研究领域的目标系统扩展到各种类型的固态材料, 包括无机, 有机, 和金属-有机框架, 利用自旋晶格联轴器巧妙5,6,7,8,9。然而, 室温操作, 必须完成, 以实际利用我的材料与他们的我联轴器, 仍然是一个具有挑战性的问题, 并报告了非常有限的单相材料的室温magnetoelectrics 至今10。
液体水晶, 拥有一个取向顺序, 有时以部份位置一, 也被审查了关于我材料在最近岁月11,12,13,14,15. 液晶作为我材料的优点之一是它们的工作温度, 因为液态晶体相通常在室温下稳定。我的一个例子液晶报告到目前为止是一个复合体磁性纳米血小板与垂直磁性各向异性和液晶显示的向列相, 称为最简单的液晶相, 只有一维取向命令15。通过对耦合血小板的电场操作和分子方向的分析, 表明了电场对磁化的影响。
最近, 提出了另一个独特的战略, 以建立在液态晶体的我的作用,16。这一策略的重点是创建一个手性 smectic C (SmC *) 阶段与一维位置顺序, 导致一个扩散层结构称为 smectic 层。SmC * 相的一个特征是分子取向向量n与局部电偶极矩p耦合。这种相关性是由杆状成分分子的倾斜方向与 smectic 层法线n0的结合, 以及在分子中的手性诱导镜 (和反转) 对称断裂提供的。从对称性的角度, 前者将D∞h (所谓的 SmA 相、图 1A) 的对称性改变为C2h (即所谓 SmC 相、图 1B) 和后者打破c2h的镜像对称性, 使对称度降低为c2 (SmC * 阶段, 参见图 1C中的每一层)。在每个 SmC * 层中, 允许沿C2轴存在有限极化, 这对n0和n都是正常的。n和p之间的强耦合是液晶中铁电性的必要条件。在 SmC * 阶段, n以螺旋方式通过图层 (图 1C) 对齐, 因此没有宏观极化。这种液晶中的铁电性是通过使用强表面效应来实现的, 它稳定了n被称为表面稳定铁电液晶 (SSFLC) 状态的均匀取向状态 (图 1D)。应该指出的是, 铁电极化反转总是伴随着双稳态方向状态的开关, 通过n和p17之间的耦合。作为逆效应, SmC * 相的分子取向的变化预期会引起电极化的变化。通过磁性元素和/或在液晶分子中的芳香环上的旋转引起的磁各向异性, 以及由于分子相互作用较弱而在液态晶体状态下的n的弹性, n是也可由磁场调谐。因此, SmC * 相可以转化为磁场诱导的均匀定向状态, 类似于 SSFLC 状态。因此, 当宏观极化的发展是由n和p的均匀对准, 在所有层中产生时, 直接的我效应, 通过磁场诱导电极化。
我们介绍的程序, 以准备液晶细胞的调查我的联结和方法, 以检测我的效果。本文详细地介绍了一种制备液晶细胞的方法, 前18。在这里, 我们修改了这个方法的介电和我的测量。在这里详细介绍了该方法, 我们检测到磁调谐电极化, 即直接我的作用, 在液晶显示 SmC * 阶段在室温下。

<table>
	<tbody>
		<tr>
			<td>Material</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Compound 1: Figure 4(A)</td>
			<td>DIC Co., Ltd.</td>
			<td>&#8211;N/A</td>
			<td>PYP-8O8</td>
		</tr>
		<tr>
			<td>Compound 2: Figure 4(B)</td>
			<td>DIC Co., Ltd.</td>
			<td>N/A</td>
			<td>PYP-10O10F</td>
		</tr>
		<tr>
			<td>ITO-coated glass substrates</td>
			<td>Sigma-Aldrich Inc.</td>
			<td>703192-10PK</td>
			<td></td>
		</tr>
		<tr>
			<td>Detergent</td>
			<td>Wako Pure Chemical Industries, Ltd.</td>
			<td>031-10401</td>
			<td></td>
		</tr>
		<tr>
			<td>Alignment layer planer</td>
			<td>JSR Co., Ltd.</td>
			<td>AL1254</td>
			<td></td>
		</tr>
		<tr>
			<td>Spacer</td>
			<td>Teijin Film Solutions Co., Ltd.</td>
			<td>Q51-12</td>
			<td></td>
		</tr>
		<tr>
			<td>Glue</td>
			<td>Huntsman Inc.</td>
			<td>ARALDITE RT30</td>
			<td>For gluing two substrates</td>
		</tr>
		<tr>
			<td>Glue</td>
			<td>M&#38;I Materials ltd.</td>
			<td>Apiezon H Grease</td>
			<td>For gluing a cell and homemade insert</td>
		</tr>
		<tr>
			<td>Silver paste</td>
			<td>Fujikura Kasei Co., Ltd.</td>
			<td>D-753</td>
			<td></td>
		</tr>
		<tr>
			<td>Equipment</td>
			<td></td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Ultrasonic cleaner</td>
			<td>AS ONE Corp.</td>
			<td>AS52GTU</td>
			<td></td>
		</tr>
		<tr>
			<td>Spin coater</td>
			<td>Mikasa Co. Ltd.</td>
			<td>1H-D7</td>
			<td></td>
		</tr>
		<tr>
			<td>Polarized optical microscope</td>
			<td>Nikon Co., Ltd.</td>
			<td>ECLIPSE LV100N POL</td>
			<td></td>
		</tr>
		<tr>
			<td>Short-pass filter</td>
			<td>Thorlabs Inc.</td>
			<td>FB600-40</td>
			<td></td>
		</tr>
		<tr>
			<td>Optical spectrometer</td>
			<td>Ocean Optics Inc.</td>
			<td>USB2000+UV-VIS</td>
			<td></td>
		</tr>
		<tr>
			<td>Differential thermal analyzer</td>
			<td>Rigaku Co., Ltd.</td>
			<td>Thermo plus EVO2</td>
			<td></td>
		</tr>
		<tr>
			<td>Superconducting magnet</td>
			<td>Quantum Design Inc.</td>
			<td>PPMS</td>
			<td></td>
		</tr>
		<tr>
			<td>LCR meter</td>
			<td>Keysight Technologies Ltd.</td>
			<td>E4980A</td>
			<td></td>
		</tr>
		<tr>
			<td>Electrometer</td>
			<td>Keithley Instruments Inc.</td>
			<td>6517A</td>
			<td></td>
		</tr>
	</tbody>
</table>

measuring magnetically-tuned ferroelectric polarization in liquid crystals

材料显示, 磁性和 (铁) 电之间的耦合现象,即电磁效应, 引起了很大的关注, 因为他们的潜在应用, 未来的设备技术, 如传感器和存储。然而, 通常使用含有磁性金属离子 (或自由基) 材料的常规方法有一个主要问题: 只有少数材料被发现在室温下显示耦合现象。最近, 我们提出了一种实现室温 magnetoelectrics 的新方法。与传统的方法相反, 我们的替代方案侧重于一种完全不同的材料, 即 "液晶", 不含磁性金属离子。在这种液晶中, 磁场可以通过分子的磁性各向异性来控制组成分子的取向态和相应的电极化;这是一个空前的磁电效应机制。在这一背景下, 本文提供了一种测量磁场诱发的铁电性质的协议, 即在液晶中的直接磁磁场效应。在此方法中, 我们成功地检测到在室温下液晶手性 smectic C 相的磁调谐电极化。结合构成分子的灵活性, 直接影响磁电反应, 引入的方法将使液晶细胞获得更多的功能, 室温 magnetoelectrics 和相关光学材料。

只有当观察到液态晶体样品中的 i 效应时, 该协议才被认为是成功的。在这里, 我们测量了直接的我的作用, 在一个液晶样品所编写的上述程序。对于测量, 在平面磁场中应用的角度倾斜由约45°从摩擦方向 (正常到 smectic 层), 因为最大的磁场诱导极化检测在这个配置16。
图 9A显示了电极化?...

Watch this Scientific Journal Video about Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals at JoVE.com

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

在本报告中, 我们提出了一种检验直接磁电效应的协议,即在液晶中应用磁场来诱导铁磁极化。该协议提供了一个独特的方法, 支持的柔软的液晶, 以实现室温 magnetoelectrics。

液晶中磁调谐铁电极化的测量

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due ...

measuring-magnetically-tuned-ferroelectric-polarization-liquid

Research

JoVE Journal

Engineering

8.7K 次观看.  Osaka University. 在本报告中, 我们提出了一种检验直接磁电效应的协议,即在液晶中应用磁场来诱导铁磁极化。该协议提供了一个独特的方法, 支持的柔软的液晶, 以实现室温 magnetoelectrics。

视频: Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

Revealing Dynamic Processes of Materials in Liquids Using Liquid Cell Transmission Electron Microscopy

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted significant interests across the research fields of materials science, physics, chemistry and biology. The key enabling technology is a liquid cell. We fabricate liquid cells with thin viewing windows through a sequential microfabrication process, including silicon nitride membrane deposition, photolithographic patterning, wafer etching, cell bonding, etc. A liquid cell with the dimensions of a regular TEM grid can fit in any standard TEM sample holder. About 100 nanoliters reaction solution is loaded into the reservoirs and about 30 picoliters liquid is drawn into the viewing windows by capillary force. Subsequently, the cell is sealed and loaded into a microscope for in situ imaging. Inside the TEM, the electron beam goes through the thin liquid layer sandwiched between two silicon nitride membranes. Dynamic processes of nanoparticles in liquids, such as nucleation and growth of nanocrystals, diffusion and assembly of nanoparticles, etc., have been imaged in real time with sub-nanometer resolution. We have also applied this method to other research areas, e.g., imaging proteins in water. Liquid cell TEM is poised to play a major role in revealing dynamic processes of materials in their working environments. It may also bring high impact in the study of biological processes in their native environment.

We have developed a self-contained liquid cell, which allows imaging through liquids using a transmission electron microscope. Dynamic processes of nanoparticles in liquids can be revealed in real time with sub-nanometer resolution.

在液体中使用液体池透射电子显微镜揭示材料的动态过程

The recent development for in situ transmission electron microscopy, which allows imaging through liquids with high spatial resolution, has attracted ...

科研

工程学

Ultrasound Velocity Measurement in a Liquid Metal Electrode

A growing number of electrochemical technologies depend on fluid flow, and often that fluid is opaque. Measuring the flow of an opaque fluid is inherently more difficult than measuring the flow of a transparent fluid, since optical methods are not applicable. Ultrasound can be used to measure the velocity of an opaque fluid, not only at isolated points, but at hundreds or thousands of points arrayed along lines, with good temporal resolution. When applied to a liquid metal electrode, ultrasound velocimetry involves additional challenges: high temperature, chemical activity, and electrical conductivity. Here we describe the experimental apparatus and methods that overcome these challenges and allow the measurement of flow in a liquid metal electrode, as it conducts current, at operating temperature. Temperature is regulated within &#177;2 &#176;C using a Proportional-Integral-Derivative (PID) controller that powers a custom-built furnace. Chemical activity is managed by choosing vessel materials carefully and enclosing the experimental setup in an argon-filled glovebox. Finally, unintended electrical paths are carefully prevented. An automated system logs control settings and experimental measurements, using hardware trigger signals to synchronize devices. This apparatus and these methods can produce measurements that are impossible with other techniques, and allow optimization and control of electrochemical technologies like liquid metal batteries.

Ultrasound velocimetry is used to study mixing by fluid flow in liquid metal electrodes. The focus of this manuscript is to illustrate the methods used for making precise, spatially-resolved ultrasound measurements while limiting oxidation and controlling and monitoring temperature, applied current, and the heater power being supplied.

超声速度测量的液态金属电极

A growing number of electrochemical technologies depend on fluid flow, and often that fluid is opaque. Measuring the flow of an opaque fluid is inherently ...

Selective Area Modification of Silicon Surface Wettability by Pulsed UV Laser Irradiation in Liquid Environment

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of biosensing devices. We report on a protocol of using KrF and ArF lasers irradiating Si (001) samples immersed in a liquid environment with low number of pulses and operating at moderately low pulse fluences to induce Si wettability modification. Wafers immersed for up to 4 hr in a 0.01% H2O2/H2O solution did not show measurable change in their initial contact angle (CA) ~75&#176;. However, the 500-pulse KrF and ArF lasers irradiation of such wafers in a microchamber filled with 0.01% H2O2/H2O solution at 250 and 65 mJ/cm2, respectively, has decreased the CA to near 15&#176;, indicating the formation of a superhydrophilic surface. The formation of OH-terminated Si (001), with no measurable change of the wafer&#8217;s surface morphology, has been confirmed by X-ray photoelectron spectroscopy and atomic force microscopy measurements. The selective area irradiated samples were then immersed in a biotin-conjugated fluorescein-stained nanospheres solution for 2 hr, resulting in a successful immobilization of the nanospheres in the non-irradiated area. This illustrates the potential of&#160;the method for selective area biofunctionalization and fabrication of advanced Si-based biosensing architectures. We also describe a similar protocol of irradiation of wafers immersed in methanol (CH3OH) using ArF laser operating at pulse fluence of 65 mJ/cm2 and in situ formation of a strongly hydrophobic surface of Si (001) with the CA of 103&#176;. The XPS results indicate ArF laser induced formation of Si&#8211;(OCH3)x compounds responsible for the observed hydrophobicity. However, no such compounds were found by XPS on the Si surface irradiated by KrF laser in methanol, demonstrating the inability of the KrF laser to photodissociate methanol and create -OCH3 radicals.

We report on a process of in situ alteration of HF treated Si (001) surface into a hydrophilic or hydrophobic state by irradiating samples in microfluidic chambers filled with&#160;H2O2/H2O solution (0.01%-0.5%) or methanol solutions using pulsed UV laser of a relative low pulse fluence.

硅表面润湿性的选择区域改性脉冲紫外激光照射在液体环境

The wettability of silicon (Si) is one of the important parameters in the technology of surface functionalization of this material and fabrication of ...

Automation of Mode Locking in a Nonlinear Polarization Rotation Fiber Laser through Output Polarization Measurements

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a new and inexpensive procedure to force mode locking in a pre-adjusted nonlinear polarization rotation fiber laser. This procedure is based on the detection of a sudden change in the output polarization state when mode locking occurs. This change is used to command the alignment of the intra-cavity polarization controller in order to find mode-locking conditions. More specifically, the value of the first Stokes parameter varies when the angle of the polarization controller is swept and, moreover, it undergoes an abrupt variation when the laser enters the mode-locked state. Monitoring this abrupt variation provides a practical easy-to-detect signal that can be used to command the alignment of the polarization controller and drive the laser towards mode locking. This monitoring is achieved by feeding a small portion of the signal to a polarization analyzer measuring the first Stokes parameter. A sudden change in the read out of this parameter from the analyzer will occur when the laser enters the mode-locked state. At this moment, the required angle of the polarization controller is kept fixed. The alignment is completed. This procedure provides an alternate way to existing automating procedures that use equipment such as an optical spectrum analyzer, an RF spectrum analyzer, a photodiode connected to an electronic pulse-counter or a nonlinear detecting scheme based on two-photon absorption or second harmonic generation. It is suitable for lasers mode locked by nonlinear polarization rotation. It is relatively easy to implement, it requires inexpensive means, especially at a wavelength of 1550 nm, and it lowers the production and operation costs incurred in comparison to the above-mentioned techniques.

A protocol to detect and automate mode locking in a pre-adjusted nonlinear polarization rotation fiber laser is presented. The detection of a sudden change in the output polarization state when mode locking occurs is used to command the alignment of an intra-cavity polarization controller in order to find mode-locking conditions.

锁模自动化的非线性偏振旋转光纤激光器通过输出偏振测量

When a laser is mode-locked, it emits a train of ultra-short pulses at a repetition rate determined by the laser cavity length. This article outlines a ...

Sub-nanometer Resolution Imaging with Amplitude-modulation Atomic Force Microscopy in Liquid

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown that when operated in amplitude-modulation (tapping) mode, atomic or molecular-level resolution images can be achieved over a wide range of soft and hard samples in liquid. In these situations, small oscillation amplitudes (SAM-AFM) enhance the resolution by exploiting the solvated liquid at the surface of the sample. Although the technique has been successfully applied across fields as diverse as materials science, biology and biophysics and surface chemistry, obtaining high-resolution images in liquid can still remain challenging for novice users. This is partly due to the large number of variables to control and optimize such as the choice of cantilever, the sample preparation, and the correct manipulation of the imaging parameters. Here, we present a protocol for achieving high-resolution images of hard and soft samples in fluid using SAM-AFM on a commercial instrument. Our goal is to provide a step-by-step practical guide to achieving high-resolution images, including the cleaning and preparation of the apparatus and the sample, the choice of cantilever and optimization of the imaging parameters. For each step, we explain the scientific rationale behind our choices to facilitate the adaptation of the methodology to every user's specific system.

We present a method for achieving sub-nanometer resolution images with amplitude-modulation (tapping mode) atomic force microscopy in liquid. The method is demonstrated on commercial atomic force microscopes. We explain the rationale behind our choices of parameters and suggest strategies for resolution optimization.

亚纳米级分辨率成像与调幅原子力显微镜在液体

Atomic force microscopy (AFM) has become a well-established technique for nanoscale imaging of samples in air and in liquid. Recent studies have shown ...

Studying Dynamic Processes of Nano-sized Objects in Liquid using Scanning Transmission Electron Microscopy

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a microfluidic chamber assembled in the specimen holder for Transmission Electron Microscopy (TEM) and STEM. The microfluidic system consists of two silicon microchips supporting thin Silicon Nitride (SiN) membrane windows. This article describes the basic steps of sample loading and data acquisition. Most important of all is to ensure that the liquid compartment is correctly assembled, thus providing a thin liquid layer and a vacuum seal. This protocol also includes a number of tests necessary to perform during sample loading in order to ensure correct assembly. Once the sample is loaded in the electron microscope, the liquid thickness needs to be measured. Incorrect assembly may result in a too-thick liquid, while a too-thin liquid may indicate the absence of liquid, such as when a bubble is formed. Finally, the protocol explains how images are taken and how dynamic processes can be studied. A sample containing AuNPs is imaged both in pure water and in saline.

This protocol describes the operation of a liquid flow specimen holder for scanning transmission electron microscopy of AuNPs in water, as used for the observation of nanoscale dynamic processes.

使用扫描透射电子显微镜研究纳米大小的物体的动态过程中的液体

Samples fully embedded in liquid can be studied at a nanoscale spatial resolution with Scanning Transmission Electron Microscopy (STEM) using a ...

Orientational Transition in a Liquid Crystal Triggered by the Thermodynamic Growth of Interfacial Wetting Sheets

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve desired molecular orientation states in LC displays, the "static" surface property of LCs, so-called surface anchoring, has been intensively studied. As a rule of thumb, once the initial orientation of LCs is "locked" by specific surface treatments, such as rubbing or treatment with a specific alignment layer, it hardly changes with temperature. Here, we present a system exhibiting an orientational transition upon temperature variation, which conflicts with the consensus. Right on the transition, the bulk LC molecules experience the orientational rotation, with 90&#176; between the planar (P) orientation at high temperatures and the vertical (V) orientation at low temperatures in the first-order transitional manner. We have tracked thermodynamic surface anchoring behavior by means of polarizing optical microscopy (POM), dielectric spectroscopy (DS), high-resolution differential scanning calorimetry (HR-DSC), and grazing incidence X-ray diffraction (GI-XRD) and reached a plausible physical explanation: that the transition is triggered by a growth of surface wetting sheets, which impose the V orientation locally against the P orientation in the bulk. This landscape would provide a general link explaining how the equilibrium bulk orientation is affected by surface-localized orientation in many LC systems. In our characterization, POM and DS are advantageous by offering information on the spatial distribution of the orientation of LC molecules. HR-DSC gives information about the precise thermodynamic information on transitions, which cannot be addressed by conventional DSC instruments due to limited resolution. GI-XRD provides information on surface-specific molecular orientation and short-range orderings. The goal of this paper is to present a protocol for preparing a sample that exhibits the transition and to demonstrate how the thermodynamic structural variation, both in the bulk and on surfaces, can be analyzed through the abovementioned methods.

Here, we present a protocol to trigger an orientational transition of a liquid crystal in response to temperature. Methodologies are described for preparing a sample in order to observe the transition and the detailed transitional evolution.

由界面润湿片的热力学生长触发的液晶中的定向转变

In liquid crystal (LC) physical chemistry, molecules near the surface play a great role in controlling bulk orientation. Thus far, mainly to achieve ...

Experimental Methods for Spin- and Angle-Resolved Photoemission Spectroscopy Combined with Polarization-Variable Laser

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser (laser-SARPES), and demonstrate a power of this technique for studying solid state physics. Laser-SARPES achieves two great capabilities. Firstly, by examining orbital selection rule of linearly polarized lasers, orbital selective excitation can be carried out in SAPRES experiment. Secondly, the technique can show full information of a variation of the spin quantum axis as a function of the light polarization. To demonstrate the power of the collaboration of these capabilities in laser-SARPES, we apply this technique for the investigations of spin-orbit coupled surface states of Bi2Se3. This technique affords to decompose spin and orbital components from the spin-orbit coupled wavefunctions. Moreover, as a representative advantage of using the direct spin detection collaborated with the polarization-variable laser, the technique unambiguously visualizes the light polarization dependence of the spin quantum axis in three-dimension. Laser-SARPES dramatically increases a capability of photoemission technique.

Here, we combine polarization-variable 7-eV laser with spin- and angle-resolved photoemission technique to visualize the spin-orbital coupling effect in solid states.

自旋角分辨光电子光谱与偏振变激光相结合的实验方法

The goal of this protocol is to present how to perform spin- and angle-resolved photoemission spectroscopy combined with polarization-variable 7-eV laser ...

A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on high-density data storage and low-power consumption capabilities. However, the high-quality oxide based nonvolatile memory on flexible substrates is often constrained by the material characteristics and the inevitable high-temperature fabrication process. In this paper, a protocol is proposed to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica. The versatile deposition technique and measurement method enable the fabrication of flexible yet single-crystalline non-volatile memory elements necessary for the next generation of smart devices.

In this paper, we present a protocol to directly grow an epitaxial yet flexible lead zirconium titanate memory element on muscovite mica.

基于范德华 Heteroepitaxy 的柔性铁电元件制备及测量方法

Flexible non-volatile memories have received much attention as they are applicable for portable smart electronic device in the future, relying on ...

Measurement of Dynamic Force Acted on Water Strider Leg Jumping Upward by the PVDF Film Sensor

This study aimed to make an explanation for the phenomenon in nature that water strider usually jumps or glides on the water surface easily but quickly, with its peak locomotion speed reaching 150 cm/s. First of all, we observed the microstructure and hierarchy of water strider legs using the scanning electron microscope. On the basis of the observed morphology of the legs, a theoretical model of the detachment from water surface was established, which explained water striders' capability to slide on water surface effortlessly in terms of energy reduction. Secondly, a dynamic force measurement system was devised using the PVDF film sensor with excellent sensitivity, which could detect the whole interaction process. Subsequently, a single leg in contact with water was pulled upward at different speeds, and the adhesion force was measured at the same time. The results of the departing experiment suggested a deep understanding of the fast jumping of water striders.

The protocol here is dedicated to investigating the free and quick maneuvering of water strider on water surface. The protocol includes observing the microstructure of legs and measuring the adhesion force when departing from water surface at different speeds.

PVDF 薄膜传感器对水黾腿跳起动力的测量

This study aimed to make an explanation for the phenomenon in nature that water strider usually jumps or glides on the water surface easily but quickly, ...