The authors acknowledge many useful discussions with M. Caggioni and support from Proctor and Gamble in the form of an internship for NAB.

在设备1.准备一次性使用的材料<ol><li>管的制备<ol><li>切管分为15厘米的段。管具有1.6毫米内径和3.2毫米的外径。 </li><li>杭管段垂直使用磁带。将纸巾筒下方，以收集多余的含氟聚合物溶液。 </li><li>注入100微升含氟聚合物溶液到使用注射器，使得其将与在内壁全周接触每个管段的顶部开口。 </li><li>允许管段代替悬挂1小时以除去含氟聚合物溶液过量。 </li><li>清理出从管未滴出的底面侧的含氟聚合物溶液。从悬挂位置拆下油管和处置纸巾。 </li><li>地方管道段到烘箱中在100℃下进行1小时退火该氟聚合物涂覆层。 </li><li>从烤箱中取出管段。使用镊子，作为管赛格将会进行热。 </li></ol></li><li>稀释磁珠溶液的制备<ol><li>计算以获得所需的结转量，如通过结转量和MB 图2质量所示之间的关系来确定所需的磁珠浓度。 注：原MB的溶液具有1克在50毫升溶液MB的。考虑20微升的测试腔容积，稀释用蒸馏水原始MB的溶液至6：4的比例（MB溶液：水）精制，得到的〜0.4微升结转量。调整时，不同的结转量所需的稀释比例。 </li><li>放置20ml的样品瓶到微平衡。零平衡。 </li><li>搅动磁珠溶液的容器中，然后用微量移液器撤回0.6毫升</li><li>分装移液溶液进入资产负债样品瓶。 </li><li>分配0.4毫升蒸馏水放入样品瓶。 </li></ol></li><li>荧光染料升iquid准备<ol><li>通过涡旋将溶液1分钟溶解染料入DI水中的2重量％。 </li></ol></li></ol> 2.准备荧光实验实验装置<ol><li>制备管设备。 <ol><li>插入阴路厄锁定连接器在管线上的一端。 </li><li>将管放入一个路厄锁注射器，其具有3 ml的体积和0.1ml毕业。 </li><li>将注射器插入注射器泵，并设置进料速率为2毫升/小时。 </li><li>为准确地插入的液体进入管道，使用注射泵撤回包含磁性珠和荧光染料的溶液。 </li><li>刀片20微升磁珠溶液进入管中，使用注射泵撤出。这种液体段被称为测试室（试验室容积可以根据实验而变化）。涡容器与磁珠溶液1分钟，然后用手在搅动<html>停药周期形成均匀MB分散体。 </li><li>后测试室液体的插入结束后，撤回6微升的空气进入管。空气的这种量将在后面形成在两液体段之间的阀。 </li><li>后空气间隙插入完成，开始撤出180微升液体与荧光染料。这种液体段被称为储。储集器容积可以根据实验而变化。更大的容器体积是有利的，以减少染料浓度的变化。 </li><li>放置一个第二阴鲁尔锁连接器到管的另一端。 </li><li>从注射器取下管装置。 </li><li>放置鲁尔锁帽上的装置的两端。 </li></ol></li><li>光学设置的荧光实验<ol><li>打开连接于倒置显微镜的所有组件。 </li><li>打开电脑，打开显微镜成像软件。 </li></ol></li></ol>对于荧光实验“&gt; 3。实验步骤<ol><li>以试验室和水库的初始荧光强度测量使用倒置显微镜。当分析样品的荧光，确保该焦点是在中心位置（在x和y方向上）的管内的液体一段。在数据表格中记录测量。 </li><li>放置设备通过立方体磁铁，使得磁珠所有分离到一个区域中的测试室的顶部。通过移动设备在磁铁（〜10秒）的顶部传送珠到储存器。 1英寸的钕磁铁的立方体是等级N48与45.6公斤拉力。 </li><li>一旦磁珠簇通过空气间隙并进入储存器传送，通过将装置在磁铁的顶部和旋转，以释放群集内被捕获的液体搅动磁珠。继续的磁珠搅拌直至贮存的同质化已经完成（〜30-45秒）。 </li><li>放置设备上的磁铁，使得磁珠在水库所有分离到一个区域的顶部。传送磁珠簇回测试室中。 </li><li>一旦簇到达测试室，通过将装置在磁铁的顶部和旋转以释放内被困荧光液体搅动磁珠。继续的磁珠搅拌直至试验室的均化已完成（〜30-45秒）。 </li><li>取这两个测试室和储存器的荧光强度测量使用倒置显微镜。在数据表格中记录测量。 </li><li>步骤3.2-3.6重复直到两个液体段收敛到类似的荧光强度（〜100个循环）。 </li></ol>荧光数据的4数值分析<ol><li>与荧光强度数据存储到电子表格中，使用MATLAB进行数值分析。 </li><li> DERIVë方程来计算在这两个贮存器和测试室荧光强度的理论值。包括下列方程化为一个MATLAB脚本文件： 其中I是荧光强度（AU），V是体积（微升）中，n是转移的数目，R为水库，T是测试室，和C是结转。 </li><li>使用MATLAB，生成图表和分析，以确定结转量在所有实验。使用这个数据，以产生图2。 </li></ol> 5.准备表面活性剂实验实验装置<ol><li>制备管设备。 <ol><li>插入阴鲁尔锁到管的一端。 </li><li>将管放入一个路厄锁注射器。 </li><li>将注射器插入注射器泵，并设置进料速率为2毫升/小时。 </li><li>为了准确地插入液体进入管道，使用注射泵撤回含有磁珠和苏解rfactant。 </li><li>将20微升磁珠解决方案为使用注射泵抽取管。这种液体段被称为测试室（试验室容积可以根据实验而变化）。搅动容器中撤出周期用手磁珠溶液中以形成均匀的MB的分散体。 </li><li>后测试室液体的插入结束后，撤回6微升的空气进入管。空气的这种体积将在后面被称作气隙。 </li><li>经过空气间隙插入完成，开始180微升纯C12E5表面活性剂撤出。这将在后面被称作储存器。 </li></ol></li><li>光学设置为表面活性剂的实验。 <ol><li>移动注射器泵与管装置，使得测试腔室与磁珠在焦点与立体显微镜。 </li><li>放置偏振膜的片材上的LED光源的上方。滑动LED光源附着到管下方注射泵。 </li><li>附加另一个偏光片用胶带立体显微镜的镜头。可以肯定的，这两个偏振膜具有90度彼此偏移。 </li><li>安装的CCD（电荷耦合器件）照相机的立体显微镜。将相机连接到电脑，并打开图像处理软件。 </li></ol></li></ol>为表面活性剂实验6.实验步骤<ol><li>广场旁边的试验室立方体磁铁在磁铁安装在支架上。 </li><li>一旦磁珠形成集群，开始以2毫升/小时的进料速率，使得磁珠群集从测试室移动，穿过气隙，并进入表面活性剂的储存室中的管泵送液体。 </li><li>一旦磁珠组达到该储存室的中点，停止对注射器泵泵送。 </li><li>移动立方体磁铁远离管，允许磁珠以分离次减少被困在磁珠簇的液体的扩散时间。 </li><li>观看电脑屏幕，通过不同阶段来观察H 2 O / C12E5混合周期。 </li><li>一旦液体的扩散和相变完成时，将磁铁回其原目的地由储所以磁珠组建成群集。 </li><li>使用注射泵，使得磁珠簇被从表面活性剂贮器传送，穿过气隙，并撤销所述的液体返回到H 2 O的测试室。 </li><li>一旦磁珠组达到该试验室的中点，停止对注射器泵泵送。 </li><li>移动立方体磁铁远离管。这将允许磁珠来分离和将有助于减少被困在磁珠簇的液体的扩散时间。 </li><li>观看电脑屏幕，通过不同阶段来观察H 2 O / C12E5混合周期。 </l我&gt; <li>一旦液体的扩散和相变完成时，将磁铁回到其由试验室前目的地，以便所述磁珠组建成群集。 </li><li>重复步骤6.2-6.11，直到试验室显示的相变。 </li></ol>

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The authors have no competing financial interests.

在对于相图调查最常用的技术，具有不同组成和比率多个样品需要准备和必须达到热力学平衡，导致一个冗长的过程，并一个显著量的材料。有些挑战可以通过DIT使用平面毛细管和红外分析方法来解决（扩散界面运输）的方法，但没有人可以解决与低成本的投资都提出了挑战。 使用磁珠用作液体载体在此微流控“实验室中管”方法的可行性证实为使用检测相邻液体段之间的?...

为1微米的直径的数量级上的磁珠（MBS）已用于1,2-经常在微流体为基础的应用，尤其是用于生物医学装置。在这些设备中，宏模块都提供了功能，例如细胞和核酸分离，造影剂，和药物递送，仅举几例。外部（磁场）控制墨滴为基础的微流控相结合，使3个控制使用小体积（&lt;100 NL）免疫测定。中型企业也表明承诺用于液体处理4时。这种方法使用的MB对的管通过空气阀隔开内输送液体段之间的生物分子。这种方法是不一样强大其它更复杂的实验片上的设备出现在过去，但它是更简单，确实提供了一种处理液体微升尺寸的卷的能力。类似的方法最近有报道5通过哈塞尔顿小组，并应用于生物医学检测。 一个这种装置的最重要的方面是由表面张力控制用空气阀所提供的液体段的分离。的液体微升体积连接到MB被通过使用外部施加的磁场的液体段之间这个空气间隙传送。微粒的MB（从〜直径0.4-7微米，平均1.9微米）下的外部磁场的影响创建内捕获液体中的微多孔群集。这种液体截留的强度足以从一个储到下运送的MB时承受表面张力的力。通常情况下，这种效果是不希望的，因为大多数的方法只需要包含在液体6中的特定分子（例如生物标志物）的传输。然而，如在我们的工作中可以看出，这种效果可以用于成为该装置的一个有利的方面。 我们已经利用这种“实验中筒“方法， 在图1中示意性地示出，用于分析相图中的二进制材料系统。该表面活性剂C12E5已被选作鉴定的主要焦点，因为它被广泛用于工业应用，如药品，食品，化妆品等。特别地，在H 2 O / C12E5二元体系进行了研究，因为它提供了一个丰富组阶段的探索。我们的重点是该化学品混合物，即一定浓度7-9下转变为液晶相的一个具体方面。这种转变是很容易地在我们的设备通过将在光学显微镜研究偏振器以突出相边界处观察到。 能够映射相图是研究以了解涉及相转变10的动力学的非常重要的领域。精确地确定表面活性剂的用溶剂的相互作用的能力第二其它组分是至关重要的，因为它们的复杂性和许多不同的阶段11。许多其它技术先前已经用于表征相变。传统方法涉及制备许多样品，每个包括不同浓度的，并允许他们平衡，这需要冗长的处理时间和高量的样品体积的。然后，样品典型地通过光学方法如扩散界面传输（DIT），它提供了高分辨率的这样的表面活性剂组合物12,13进行分析。类似于我们已经利用的方法中，在DIT方法使用偏振光图像上不同的相的边界。

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>AccuBead</td>
			<td>Bioneer Inc.</td>
			<td>TS-1010-1</td>
			<td>Magnetic beads</td>
		</tr>
		<tr>
			<td>C12E5 Surfactant</td>
			<td>Sigma-Aldrich</td>
			<td>76437</td>
			<td></td>
		</tr>
		<tr>
			<td>Thermo Scientific Nalgene 890</td>
			<td>Fisher Scientific</td>
			<td>14176178</td>
			<td></td>
		</tr>
		<tr>
			<td>Cube Magnet</td>
			<td>Apex Magnets</td>
			<td>M1CU</td>
			<td></td>
		</tr>
		<tr>
			<td>Polarizer Film</td>
			<td>Edmund Optics</td>
			<td>38-493</td>
			<td></td>
		</tr>
		<tr>
			<td>Teflon AF</td>
			<td>Dupont</td>
			<td>400s1-100-1</td>
			<td>Fluoropolymer solution</td>
		</tr>
		<tr>
			<td>Keyacid Red Dye</td>
			<td>Keystone</td>
			<td>601-001-49</td>
			<td>Fluorescent dye</td>
		</tr>
		<tr>
			<td>Luer-Lock</td>
			<td>Cole-Parmer</td>
			<td>T-45502-12</td>
			<td>Female</td>
		</tr>
		<tr>
			<td>Luer-Lock</td>
			<td>Cole-Parmer</td>
			<td>T-45502-56</td>
			<td>Male</td>
		</tr>
		<tr>
			<td>Syringe</td>
			<td>Fisher Scientific</td>
			<td>14-823-435</td>
			<td>3 mL</td>
		</tr>
		<tr>
			<td>Syringe Pump</td>
			<td>Stoelting</td>
			<td>53130</td>
			<td></td>
		</tr>
		<tr>
			<td>Stereo Microscope</td>
			<td>Nikon</td>
			<td>SMZ-2T</td>
			<td></td>
		</tr>
		<tr>
			<td>Inverted Microscope</td>
			<td>Nikon</td>
			<td>Eclipse Ti-U</td>
			<td>The filter cube used had an excitation wavelength range from 540-580 nm and a dichroic mirror at 585 nm, allowing for photoemission ranging from 593-668 nm.</td>
		</tr>
		<tr>
			<td>Balance</td>
			<td>Denver Instruments&#160;</td>
			<td>PI-225D</td>
			<td></td>
		</tr>
		<tr>
			<td>Microscope-Mounted Camera</td>
			<td>Motic</td>
			<td>5000</td>
			<td></td>
		</tr>
	</tbody>
</table>

phase diagram characterization using magnetic beads as liquid carriers

磁珠〜1.9微米的平均直径分别用于输送的连续液段之间的液体微升体积用管为调查这些液体段的相变的目的。磁珠用磁铁，允许珠弥合相邻液体段之间的空气阀是从外部进行控制。疏水性涂层施加到管的内表面上，以提高两液体段之间的分离。施加的磁场形成的磁性珠粒的聚集体簇，即称为结转体积群集内捕获了一定量的液体。将荧光染料加到一种液体段，后面是一系列的液体转移，然后改变的荧光强度在邻近液体一段。基于测得的荧光强度变化的数值分析，每磁珠质量的结转量已经发现为〜2至3微升/毫克。允许使用几百微升比较小的液体段的这种少量的液体，提高了装置的可行性实验室中筒的方法。施加小的组成变化在液体体积的这种技术被用于分析水和表面活性剂C12E5（五乙二醇单十二烷基醚）之间的二元相图，导致更快的分析更小的样品体积比常规方法。

使用实验室中管的方法用于输送液体微升容积量与磁珠一起MATLAB进行数值分析，平均液体结转卷，磁珠质量的函数，被发现（图2）。更高质量的磁珠提供在2-3微升/毫克的速率更高的结转量。实验设置（图1）被用来观察的 H 2 O / C12E5二元体系内的相变。由于H 2 O / C12E5系统是公知的，有许多不同的阶段，它可以在图3B中可以看出，它作为参考的?...

Watch this Scientific Journal Video about Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers at JoVE.com

Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers

Here, we present a protocol to investigate multi-component phase diagrams using externally controlled magnetic beads as liquid carriers in a lab-in-tube approach. This approach can aid in applications that seek to gather further information on phase change in complex liquid systems.

相图表征使用磁珠用作液体载体

Magnetic beads with ~1.9 &#181;m average diameter were used to transport microliter volumes of liquids between contiguous liquid segments with a tube for ...

phase-diagram-characterization-using-magnetic-beads-as-liquid-carriers

Research

JoVE Journal

Engineering

12.1K 次观看.  University of Cincinnati. Here, we present a protocol to investigate multi-component phase diagrams using externally controlled magnetic beads as liquid carriers in a lab-in-tube approach. This approach can aid in applications that seek to gather further information on phase change in complex liquid systems.

视频: Phase Diagram Characterization Using Magnetic Beads as Liquid Carriers

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

Characterization of Recombination Effects in a Liquid Ionization Chamber Used for the Dosimetry of a Radiosurgical Accelerator

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via stereotactic radiotherapy where positioning accuracy allows delivering very high doses per fraction in a small volume of the patient. Dosimetric measurements on medical accelerators are conventionally realized using air-filled ionization chambers. However, in small beams these are subject to nonnegligible perturbation effects. This study focuses on liquid ionization chambers, which offer advantages in terms of spatial resolution and low fluence perturbation. Ion recombination effects are investigated for the microLion detector (PTW) used with the Cyberknife system (Accuray). The method consists of performing a series of water tank measurements at different source-surface distances, and applying corrections to the liquid detector readings based on simultaneous gaseous detector measurements. This approach facilitates isolating the recombination effects arising from the high density of the liquid sensitive medium and obtaining correction factors to apply to the detector readings. The main difficulty resides in achieving a sufficient level of accuracy in the setup to be able to detect small changes in the chamber response.

A growing number of radiation therapy devices offer the advantage of delivering the dose through very small beams to the tumor, allowing for increased conformity and higher doses per fraction. Many different detectors can be used for the dosimetry of these small fields. In the present study, the effect of ion recombination is investigated for a liquid ionization chamber using a stereotactic radiation therapy system.

重组的影响在液体电离室表征用于一个电波加速器的剂量学

Most modern radiation therapy devices allow the use of very small fields, either through beamlets in Intensity-Modulated Radiation Therapy (IMRT) or via ...

Measurement of X-ray Beam Coherence along Multiple Directions Using 2-D Checkerboard Phase Grating

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is reported. The measurements were demonstrated at the 1-BM bending magnet beamline of the Advanced Photon Source (APS) at Argonne National Laboratory (ANL). By using a 2-D checkerboard &#960;/2 phase-shift grating, transverse coherence lengths were obtained along the vertical and horizontal directions as well as along the 45&#176; and 135&#176; directions to the horizontal direction. Following the technical details specified in this paper, interferograms were measured at different positions downstream of the phase grating along the beam propagation direction. Visibility values of each interferogram were extracted from analyzing harmonic peaks in its Fourier Transformed image. Consequently, the coherence length along each direction can be extracted from the evolution of visibility as a function of the grating-to-detector distance. The simultaneous measurement of coherence lengths in four directions helped identify the elliptical shape of the coherence area of the Gaussian-shaped X-ray source. The reported technique for multiple-direction coherence characterization is important for selecting the appropriate sample size and orientation as well as for correcting the partial coherence effects in coherence scattering experiments. This technique can also be applied for assessing coherence preserving capabilities of X-ray optics.

The measurement protocol and data analysis procedure are given for obtaining transverse coherence of a synchrotron radiation X-ray source along four directions simultaneously using a single 2-D checkerboard phase grating. This simple technique can be applied for complete transverse coherence characterization of X-ray sources and X-ray optics.

使用2-D棋盘相位光栅X射线束相干测量沿多个方向

A procedure for a technique to measure the transverse coherence of synchrotron radiation X-ray sources using a single phase grating interferometer is ...

Frequency Mixing Magnetic Detection Scanner for Imaging Magnetic Particles in Planar Samples

The setup of a planar Frequency Mixing Magnetic Detection (p-FMMD) scanner for performing Magnetic Particles Imaging (MPI) of flat samples is presented. It consists of two magnetic measurement heads on both sides of the sample mounted on the legs of a u-shaped support. The sample is locally exposed to a magnetic excitation field consisting of two distinct frequencies, a stronger component at about 77 kHz and a weaker field at 61 Hz. The nonlinear magnetization characteristics of superparamagnetic particles give rise to the generation of intermodulation products. A selected sum-frequency component of the high and low frequency magnetic field incident on the magnetically nonlinear particles is recorded by a demodulation electronics. In contrast to a conventional MPI scanner, p-FMMD does not require the application of a strong magnetic field to the whole sample because mixing of the two frequencies occurs locally. Thus, the lateral dimensions of the sample are just limited by the scanning range and the supports. However, the sample height determines the spatial resolution. In the current setup it is limited to 2 mm. As examples, we present two 20 mm &#215; 25 mm p-FMMD images acquired from samples with 1 &#181;m diameter maghemite particles in silanol matrix and with 50 nm magnetite particles in aminosilane matrix. The results show that the novel MPI scanner can be applied for analysis of thin biological samples and for medical diagnostic purposes.

A scanner for imaging magnetic particles in planar samples was developed using the planar frequency mixing magnetic detection technique. The magnetic intermodulation product response from the nonlinear nonhysteretic magnetization of the particles is recorded upon a two-frequency excitation. It can be used to take 2D images of thin biological samples.

混频磁探测仪在平面样品成像磁性微粒

The setup of a planar Frequency Mixing Magnetic Detection (p-FMMD) scanner for performing Magnetic Particles Imaging (MPI) of flat samples is presented. ...

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 ...

Characterization of Ultra-fine Grained and Nanocrystalline Materials Using Transmission Kikuchi Diffraction

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and nanocrystalline materials. The traditional techniques associated with scanning electron microscopy (SEM), such as electron backscatter diffraction (EBSD), do not possess the required spatial resolution due to the large interaction volume between the electrons from the beam and the atoms of the material. Transmission electron microscopy (TEM) has the required spatial resolution. However, due to a lack of automation in the analysis system, the rate of data acquisition is slow which limits the area of the specimen that can be characterized. This paper presents a new characterization technique, Transmission Kikuchi Diffraction (TKD), which enables the analysis of the microstructure of UFG and nanocrystalline materials using an SEM equipped with a standard EBSD system. The spatial resolution of this technique can reach 2 nm. This technique can be applied to a large range of materials that would be difficult to analyze using traditional EBSD. After presenting the experimental set up and describing the different steps necessary to realize a TKD analysis, examples of its use on metal alloys and minerals are shown to illustrate the resolution of the technique and its flexibility in term of material to be characterized.

This paper provides a detailed method to characterize the microstructure of ultra-fine grained and nanocrystalline materials using a scanning electron microscope equipped with a standard electron backscatter diffraction system. Metal alloys and minerals presenting refined microstructures are analyzed using this technique, showing the diversity of its possible applications.

超细晶和纳米晶材料的表征采用透射菊池衍射

One of the challenges in microstructure analysis nowadays resides in the reliable and accurate characterization of ultra-fine grained (UFG) and ...

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape method or individual WS2 nanotubes by dispersing the suspension of WS2 nanotubes. The selected samples have been fabricated into devices by the use of the electron beam lithography and electrolyte is put on the devices. We have characterized the electronic properties of the devices under applying the gate voltage. In the small gate voltage region, ions in the electrolyte are accumulated on the surface of the samples which leads to the large electric potential drop and resultant electrostatic carrier doping at the interface. Ambipolar transfer curve has been observed in this electrostatic doping region. When the gate voltage is further increased, we met another drastic increase of source-drain current which implies that ions are intercalated into layers of WS2 and electrochemical carrier doping is realized. In such electrochemical doping region, superconductivity has been observed. The focused technique provides a powerful strategy for achieving the electric-filed-induced quantum phase transition.

Electric-field Control of Electronic States in WS2 Nanodevices by Electrolyte Gating

Here, we present a protocol to control the carrier number in solids by using the electrolyte.

用电解质浇注法对 WS2纳米器件电子态的电场控制

A method of carrier number control by electrolyte gating is demonstrated. We have obtained WS2 thin flakes with atomically flat surface via scotch tape ...

Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques

Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared on transparent membranes which are very fragile and difficult to manipulate. We present processes for the fabrication of samples with magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for Lorentz transmission electron microscopy and magnetic transmission x-ray microscopy studies. The samples are prepared on silicon nitride membranes and the fabrication consists of a spin coating, UV and electron-beam lithography, the chemical development of the resist, and the evaporation of the magnetic material followed by a lift-off process forming the final magnetic structures. The samples for the Lorentz transmission electron microscopy consist of magnetic nanodiscs prepared in a single lithography step. The samples for the magnetic x-ray transmission microscopy are used for time-resolved magnetization dynamic experiments, and magnetic nanodiscs are placed on a waveguide which is used for the generation of repeatable magnetic field pulses by passing an electric current through the waveguide. The waveguide is created in an extra lithography step.

A protocol for the fabrication of magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for transmission electron microscopy (TEM) and magnetic transmission x-ray microscopy (MTXM) studies is presented.

用透射显微技术制备氮化硅薄膜磁性纳米结构的研究

Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared ...

Measuring Magnetically-Tuned Ferroelectric Polarization in Liquid Crystals

Materials showing coupling phenomena between magnetism and (ferro)electricity, i.e., magnetoelectric effects, have attracted a great deal of attention due to their potential applications for future device technologies such as sensors and storage. However, conventional approaches, which usually utilize materials containing magnetic metal ions (or radicals), have a major problem: only a few materials have been found to show the coupling phenomena at room temperature. Recently, we proposed a new approach to achieve room-temperature magnetoelectrics. In contrast to conventional approaches, our alternative proposal focuses on a completely different material, a &#34;liquid crystal&#34;, free from magnetic metal ions. In such liquid crystals, a magnetic field can be utilized to control the orientational state of constituent molecules and the corresponding electric polarization through magnetic anisotropy of the molecules; it is an unprecedented mechanism of the magnetoelectric effect. In this context, this paper provides a protocol to measure ferroelectric properties induced by a magnetic field, that is, the direct magnetoelectric effect, in a liquid crystal. With the method detailed here, we successfully detected magnetically-tuned electric polarization in the chiral smectic C phase of a liquid crystal at room temperature. Taken together with the flexibility of constituent molecules, which directly affects the magnetoelectric responses, the introduced method will serve to allow liquid crystal cells to acquire more functions as room-temperature magnetoelectrics and associated optical materials.

In this report, we present a protocol to examine direct magnetoelectric effects, i.e., induction of ferroelectric polarization by applying magnetic fields, in liquid crystals. This protocol provides a unique approach, supported by the softness of liquid crystals, to achieve room-temperature 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 ...

Shaping the Amplitude and Phase of Laser Beams by Using a Phase-only Spatial Light Modulator

The aim of this article is to visually demonstrate the utilization of an interferometric method for encoding complex fields associated with coherent laser radiation. The method is based on the coherent sum of two uniform waves, previously encoded into a phase-only spatial light modulator (SLM) by spatial multiplexing of their phases. Here, the interference process is carried out by spatial filtering of light frequencies at the Fourier plane of certain imaging system. The correct implementation of this method allows arbitrary phase and amplitude information to be retrieved at the output of the optical system.
It is an on-axis, rather than off-axis encoding technique, with a direct processing algorithm (not an iterative loop), and free from coherent noise (speckle). The complex field can be exactly retrieved at the output of the optical system, except for some loss of resolution due to the frequency filtering process. The main limitation of the method might come from the inability to operate at frequency rates higher than the refresh rate of the SLM. Applications include, but are not limited to, linear and non-linear microscopy, beam shaping, or laser micro-processing of material surfaces.

We show how to encode the complex field of laser beams by using a single phase element. A common-path interferometer is employed to mix the phase information displayed into a phase-only spatial light modulator to finally retrieve the desired complex field pattern at the output of an optical imaging system.

利用相位空间光调制器建立激光光束的振幅和相位

The aim of this article is to visually demonstrate the utilization of an interferometric method for encoding complex fields associated with coherent laser ...