这项工作得到中国国家自然科学基金 (11402221 和11502224号批准)、强脉冲辐射模拟和效果国家重点实验室 (SKLIPR1513) 和湖南省重点研究开发计划 (no。2016WK2014)。

1. 制备柔性 PZT 薄膜
<ol><li>从云母板上剪下1厘米 x 1 厘米的云母基板。</li>
	<li>用双面胶带将这1厘米 x 1 厘米的云母基板固定在办公桌上。</li>
	<li>使用镊子剥离云母层逐层, 直到所需的厚度 (50 µm), 用千分尺测量。</li>
	<li>用薄薄的一层银漆将这个新鲜的云母基板粘贴在 5 "衬底上", 并在热板上固化120摄氏度10分钟, 牢固地将云母附着在基体上。</li>
	<li>将 pld (脉冲激光沉积) 衬底架置于 pld 腔内。</li>
	<li>选择重复速率 (例如, 10 Hz) 和激光能量 (例如, 300 兆焦耳)。</li>
	<li>将聚焦透镜移动到设置位置。</li>
	<li>打开快门并存入 5 nm CoFe2O4 (CFO) [激光能量: 300 mJ, 氧气压力:50 mTorr, 样品温度: 590 °c, 沉积时间: 5 分钟] 薄膜作为缓冲层, 通过触发激光 (图 1)。</li>
	<li>存入 20-80 nm SrRuO3 (SRO) [激光能量: 300 兆焦耳, 氧气压力: 100 mTorr, 样品温度: 680 °c, 沉积时间: 10-30 分钟] 在 CFO 缓冲层作为随后电性能测试的底部电极通过触发激光 (图 1)。</li>
	<li>存入150纳米 PZT [激光能量: 300 兆焦耳, 氧气压力: 100 mTorr, 样品温度: 650 °c, 沉积时间:60 分钟] 薄膜在 SRO 底部电极上通过触发激光 (图 1)。</li>
	<li>当温度达到室温时, 使用 N2排气室并卸下 PZT/云母样品 (图 2)。</li>
	<li>把样品放在一块玻璃上。</li>
	<li>将200µm 直径的预先设计的网格放在样品上面。将网格井固定好, 并将网格样品放入溅射腔内。</li>
	<li>使用直流溅射 (10 mA, 8 毫巴, 6 分钟) 在胶片上沉积铂顶电极。在溅射后取出样品。</li>
	<li>使用刀子或 20% HF 酸去除1毫米 x 1 毫米 PZT 部分。这是揭开底部 SRO 电极, 形成许多小的柔性铁电电容器。 注: 以 SRO 为底电极, 然后将铂放在薄膜上的电极上, 通过直流溅射形成许多小电容器来测量 PZT 薄膜的电子特性, 如图 3所示。</li>
	<li>在暴露的 SRO 上涂一层导电银, 以增加底部 SRO 电极的电导率。确保导电银可以接触暴露的 SRO。</li>
</ol>2. 铁电特性
<ol><li>弯曲试验<ol>
<li>在挠性试样的背面, 胶水一张与样品大小相同的纸, 便于将样品从一个阶段转移到另一舞台。</li>
		<li>将 PZT/云母放在铁电测试系统和半导体器件分析仪的测试板上。</li>
		<li>将铁电测试系统和半导体器件分析仪的测量探头放在 Pt 上电极上, 并将其它测量探头放在银 SRO 层上, 得到极化电场 (P E) 滞后回路, 并电容-电场 (C E) 曲线, 而样品是直。<ol>
<li>测量 P E 迟滞环与两个探头在2赫频率和 4 v 测量的 c-E 曲线与两个探头在1兆赫频率和 4 v. 删除直样品。</li>
		</ol>
</li>
		<li>使用双面胶带固定在所需模具上的柔性 PZT/云母薄膜。注意避免在测量过程中云母的滑动/滑动。</li>
		<li>将其安装在铁电测试系统和半导体器件分析仪的测试板上。</li>
		<li>将一个探针放在 Pt 顶部电极上, 而另一探头触及底部的 SRO 电极, 通过与先前使用的配置类似的银涂层 (步骤 2.1.3)。</li>
		<li>测量在各种拉伸和压缩弯曲半径下的 P e 迟滞环和 c-e 曲线 (图 4)。<ol>
<li>用两个探头以2赫频率测量 P E 迟滞环, 在 4 v 测量 C e 曲线, 两个探头的频率为1兆赫, 4 v。</li>
		</ol>
</li>
		<li>当 P e 和 C e 测量完成时, 去掉挠性 PZT 样品。</li>
	</ol>
</li>
	<li>热稳定性<ol>
<li>将 PZT/云母放在铁电测试系统和半导体器件分析仪的测试板上。</li>
		<li>在 Pt 上电极上放置一个测量探头, 并将其他测量探头放在银 SRO 层上。</li>
		<li>打开温度控制系统, 加热样品。</li>
		<li>在不同的温度下进行 P e 和 C E 测量 (25 °c, 50 °c, 75 °c, 100 °c, 125 °c, 150 °c, 175 °c)。</li>
		<li>测量完成后, 关闭加热器组件。</li>
	</ol>
</li>
	<li>弯曲 cyclability 试验<ol>
<li>将柔性 PZT/云母装入此设置的两个凹槽中。</li>
		<li>修正样品的一端, 当它从另一端弯曲时, 借助马达。</li>
		<li>使用标尺测量 PZT/云母长度以及 8 mm 弯曲过程之前马达的运动 (弯曲) 方向 (图 5)。</li>
		<li>根据公式计算运动长度 c 弯曲样品5毫米: c = L-2 rsin (升/2 R), 其中 L 是 PZT/云母的长度在直状态, R 是弯曲的半径, 并且 C 是马达的运动长度。</li>
		<li>在计算机中设置弯曲循环 (1000) 的数目 (图 6)。</li>
		<li>单击 "开始" 按钮 (图 6) 启动来回马达运动。</li>
		<li>取出样品并测量 P E 以检查铁电性质是否保留。</li>
	</ol>
</li>
</ol>

<ol>
	<li>Kim, W. Y., Lee, H. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Stable+ferroelectric+poly+(vinylidene+fluoride-trifluoroethylene)+film+for+flexible+nonvolatile+memory+application.">Stable ferroelectric poly (vinylidene fluoride-trifluoroethylene) film for flexible nonvolatile memory application.</a> IEEE Electron Device Letters. 33 (2), 260-262 (2012).</li><li>Mao, D., Quevedo-Lopez, M. A., Stiegler, H., Gnade, B. E., Alshareef, H. N. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Optimization+of+poly(vinylidene+fluoride-trifluoroethylene)+films+as+non-volatile+memory+for+flexible+electronics.">Optimization of poly(vinylidene fluoride-trifluoroethylene) films as non-volatile memory for flexible electronics.</a> Organic Electronics. 11 (5), 925-932 (2010).</li><li>Lee, G. G., 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=The+flexible+non-volatile+memory+devices+using+oxide+semiconductors+and+ferroelectric+polymer+poly(vinylidene+fluoride-trifluoroethylene).">The flexible non-volatile memory devices using oxide semiconductors and ferroelectric polymer poly(vinylidene fluoride-trifluoroethylene).</a> Applied Physics Letters. 99 (1), 012901-012903 (2011).</li><li>Kim, R. H., 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=Non-volatile+organic+memory+with+sub-millimeter+bending+radius.">Non-volatile organic memory with sub-millimeter bending radius.</a> Nature Communications. 5, 3583-3594 (2014).</li><li>Liu, J., 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=Fabrication+of+Flexible,+All-Reduced+graphene+oxide+non-volatile+memory+devices.">Fabrication of Flexible, All-Reduced graphene oxide non-volatile memory devices.</a> Advanced Materials. 25 (2), 233-238 (2013).</li><li>Ji, Y., 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=Stable+switching+characteristics+of+organic+nonvolatile+memory+on+a+bent+flexible+substrate.">Stable switching characteristics of organic nonvolatile memory on a bent flexible substrate.</a> Advanced Materials. 22 (28), 3071-3075 (2010).</li><li>Ghoneim, M. T., 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=Thin+PZT-based+ferroelectric+capacitors+on+flexible+silicon+for+nonvolatile+memory+applications.">Thin PZT-based ferroelectric capacitors on flexible silicon for nonvolatile memory applications.</a> Advanced Electronic Materials. 1 (6), 1500045-1500054 (2015).</li><li>Ghoneim, M. T., Hussain, M. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+harsh+environment+operation+of+flexible+ferroelectric+memory+integrated+with+PZT+and+silicon+fabric.">Study of harsh environment operation of flexible ferroelectric memory integrated with PZT and silicon fabric.</a> Applied. Physics. Letters. 107 (5), 052904-052908 (2015).</li><li>Zuo, Z., 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=Preparation+and+ferroelectric+properties+of+freestanding+Pb(Zr,Ti)O3+thin+membranes.">Preparation and ferroelectric properties of freestanding Pb(Zr,Ti)O3 thin membranes.</a> Journal of Physics D: Applied Physics. 45 (18), 185302-185306 (2012).</li><li>Kingon, A. I., Srinivasan, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Lead+zirconate+titanate+thin+films+directly+on+copper+electrodes+for+ferroelectric,+dielectric+and+piezoelectric+applications.">Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications.</a> Nature Materials. 4 (3), 233-237 (2005).</li><li>Shelton, C. T., Gibbons, B. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Epitaxial+Pb(Zr,Ti)O3+thin+films+on+flexible+substrates.">Epitaxial Pb(Zr,Ti)O3 thin films on flexible substrates.</a> Journal of the American Ceramic Society. 94 (10), 3223-3226 (2011).</li><li>Rho, J., 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=PbZrxTi1&#8722;xO3+Ferroelectric+thin-film+capacitors+for+flexible+nonvolatile+memory+applications.">PbZrxTi1&#8722;xO3 Ferroelectric thin-film capacitors for flexible nonvolatile memory applications.</a> IEEE Electron Device Letters. 31 (9), 1017-1019 (2010).</li><li>Bretos, I., 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=Activated+Solutions+Enabling+Low-Temperature+processing+of+functional+ferroelectric+oxides+for+flexible+electronics.">Activated Solutions Enabling Low-Temperature processing of functional ferroelectric oxides for flexible electronics.</a> Advanced Materials. 26 (9), 1405-1409 (2014).</li><li>Tsagarakis, E. D., Lew, C., Thompson, M. O., Giannelis, E. P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Nanocrystalline+barium+titanate+films+on+flexible+plastic+substrates+via+pulsed+laser+annealing.">Nanocrystalline barium titanate films on flexible plastic substrates via pulsed laser annealing.</a> Applied Physics Letters. 89 (20), 202910-202912 (2006).</li><li>Bakaul, S. R., 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=High+speed+epitaxial+perovskite+memory+on+flexible+substrates.">High speed epitaxial perovskite memory on flexible substrates.</a> Advanced Materials. 29 (11), 1605699-1605703 (2017).</li><li>Li, C. I., 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=Van+der+Waal+epitaxy+of+flexible+and+transparent+VO2+film+on+muscovite.">Van der Waal epitaxy of flexible and transparent VO2 film on muscovite.</a> Chemistry of Materials. 28 (11), 3914-3919 (2016).</li><li>Ma, C. H., 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=Van+der+Waals+epitaxy+of+functional+MoO2+film+on+mica+for+flexible+electronics.">Van der Waals epitaxy of functional MoO2 film on mica for flexible electronics.</a> Applied Physics Letters. 108 (25), 253104-253108 (2016).</li><li>Bitla, Y., 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=Oxide+heteroepitaxy+for+flexible+optoelectronics.">Oxide heteroepitaxy for flexible optoelectronics.</a> ACS Applied Materials &amp; Interfaces. 8 (47), 32401-32407 (2016).</li><li>Wu, P. C., 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=Heteroepitaxy+of+Fe3O4/muscovite:+A+new+perspective+for+flexible+spintronics.">Heteroepitaxy of Fe3O4/muscovite: A new perspective for flexible spintronics.</a> ACS Applied Materials &amp; Interfaces. 8 (49), 33794-33801 (2016).</li><li>Jiang, J., 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=Flexible+ferroelectric+element+based+on+van+der+Waals+heteroepitaxy.">Flexible ferroelectric element based on van der Waals heteroepitaxy.</a> Science Advances. 3 (6), e1700121-e1700128 (2017).</li><li>Amrillah, T., 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=Flexible+multiferroic+bulk+heterojunction+with+giant+magnetoelectric+coupling+via+van+der+waals+epitaxy.">Flexible multiferroic bulk heterojunction with giant magnetoelectric coupling via van der waals epitaxy.</a> ACS Nano. 11 (6), 6122-6130 (2017).</li><li>Bitla, Y., Chu, Y. H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=MICAtronics:+A+new+platform+for+&#64258;exible+X-tronics.">MICAtronics: A new platform for &#64258;exible X-tronics.</a> Flat Chem. 3, 26-42 (2017).</li><li>Chu, Y. H. <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+oxide+heteroepitaxy.">Van der Waals oxide heteroepitaxy.</a> Quantum Materials. 2 (1), 67-71 (2017).</li></ol>

作者没有竞争的金融利益来披露。

铁电元件制造的关键步骤在于使用清洁均匀/平坦的基体表面。虽然新剥离的云母表面是原子平滑的, 但有必要注意防止表面遭受可见分裂, 分裂层, 裂纹, 夹杂物,等.在压电陶瓷层沉积后, 试样在高氧压力 (200-500 乇), 以减少氧气空缺。前原位顶铂电极通过预定义的网格沉积, 形成许多 Pt/PZT/SRO 电容器元件。为了进行弯曲试验, 样品附着在一张类似尺寸的纸上, 使样品在不同的模具之间容?...

柔性非易失性记忆元件 (NVME) 的成功制造在充分利用柔性电子的潜力方面发挥着关键作用。除数据存储、信息处理和通信外, NVME 应具有重量轻、成本低、功耗低、速度快、存储密度高等特点。钙钛矿铅 (锆、钛) O3 (PZT) 作为一种普遍应用的系统, 考虑到其大极化、快速极化开关、高居里温度、低胁迫场和高压电系数。在铁电非挥发性存储器中, 外部电压脉冲可以在两个稳定方向之间切换两个残余偏振, 用 "0" 和 "1" 表示。它是非易失性的, 写/读过程可以在纳秒内完成。NVME 基于有机1,2,3,4,5,6 和无机7,8,9,10 、11、12、13、14、15铁电材料已在柔性基板上尝试。然而, 这种集成不仅受到基体的高温生长能力的限制, 而且由于其粗糙的表面而使器件性能下降、电流泄漏和电子短路。尽管有很有希望的结果, 但考虑到复杂的多步骤过程, 诸如衬底8和外延层在柔性基板上传输的交替策略15的生存能力受到限制。转让的不可预测性和有限的适用性。
基于上述原因, 探索合适的基底, 能够克服软基板的有限热和操作稳定性, 进一步推进柔性电子学, 是至关重要的。天然白云母云母 (卡尔2(铝硅 3 O 10) (OH) 2) 基板, 具有原子平滑表面、高热稳定性、化学惰性、高透明度、机械灵活性和与当前制造方法的兼容性可以用来有效地处理这些问题。型单斜云母的二维层状结构支持范德华外延, 减少晶格和热匹配条件, 从而显著抑制基板的夹紧效果。这些优势已被利用在功能氧化物的直接增长16,17,18,19,20,21,22,最近, 由于灵活的设备应用程序, 23在白云母上。
在这里, 我们描述了一个协议, 直接生长外延, 但软钛酸锆 (PZT) 薄膜在白云母云母。这是通过脉冲激光沉积的过程, 依靠云母的多功能性, 导致范德华 heteroepitaxy。这种预制结构在刚性单晶基体上保留了外延 PZT 的所有优越性能, 具有良好的热力学稳定性。这种简单可靠的方法比多步转移和基板细化策略提供了技术上的优势, 并促进了期待已久的灵活但单晶非挥发性内存元素的开发先决条件高性能的下一代智能设备。

<table><tbody><tr><td>&lt;strong&gt;Equipment&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>hot plate</td><td>Polish</td><td>P-20</td><td></td></tr><tr><td>PLD system</td><td>PVD products</td><td>PLD 5000</td><td></td></tr><tr><td>Ferroelectric test system&amp;nbsp;</td><td>Radiant Technologies Precisions workstations&amp;nbsp;</td><td>RT66A</td><td></td></tr><tr><td>Semiconductor device analyzer&amp;nbsp;</td><td>Agilent&amp;nbsp;</td><td>B1500A</td><td></td></tr><tr><td>Bending molds</td><td>home-made</td><td></td><td>Machined teflon material</td></tr><tr><td>Bending stage</td><td>home-built</td><td></td><td>Labview interfaced setup which provides a prescise displacemnt as small as 1 micrometer</td></tr><tr><td>Sputtering system</td><td>Beijing&amp;nbsp;Elaborate</td><td>ETD-3000</td><td></td></tr><tr><td>&lt;strong&gt;Materials&lt;/strong&gt;</td><td></td><td></td><td></td></tr><tr><td>mica(001) sheets</td><td>Nilaco corporation&amp;nbsp;</td><td>990066</td><td></td></tr><tr><td>conductive silver paint</td><td>Ted Pella, INC</td><td>No.16033</td><td></td></tr><tr><td>CoFe&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;4&lt;/sub&gt; target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>SrRuO&lt;sub&gt;3&lt;/sub&gt; target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>PbZr&lt;sub&gt;0.2&lt;/sub&gt;Ti&lt;sub&gt;0.8&lt;/sub&gt;O&lt;sub&gt;3 &lt;/sub&gt;target</td><td>Kurt J.Lesker</td><td></td><td></td></tr><tr><td>Pt target</td><td>Hefei Ke jing</td><td></td><td></td></tr></tbody></table>

a fabrication and measurement method for a flexible ferroelectric element based on van der waals heteroepitaxy

灵活的非易失性记忆已受到人们的广泛关注, 因为它们适用于未来便携式智能电子设备, 依靠高密度的数据存储和低功耗的功能。然而, 柔性基板上的高质量氧化物非易失性存储器往往受制于材料特性和不可避免的高温加工过程。本文提出了一种在白云母云母上直接生长具有外延但又灵活的钛酸铅锆记忆元素的协议。这种多功能的沉积技术和测量方法使下一代智能设备所必需的灵活而单一晶体的非挥发性存储器元件得以制造。

在步骤1中概述了脉冲激光沉积技术在外延 PZT/SRO/CFO/云母薄膜上的沉积。图 1显示了增长方案,图 2显示了基于 PZT 的实际灵活的 NVM 元素。

机械稳定性是柔性器件应用的一个关键环节。在拉伸和压缩弯曲条件下, 对异质体的宏观铁电性能进行了评价。图 7a</s...

Watch this Scientific Journal Video about A Fabrication and Measurement Method for a Flexible Ferroelectric Element Based on Van Der Waals Heteroepitaxy at JoVE.com

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

本文提出了一种在白云母云母上直接生长具有外延但又灵活的钛酸铅锆记忆元素的协议。

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 ...

a-fabrication-measurement-method-for-flexible-ferroelectric-element

Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

8.2K 次观看.  Xiangtan University. 本文提出了一种在白云母云母上直接生长具有外延但又灵活的钛酸铅锆记忆元素的协议。

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

Fabrication of Spatially Confined Complex Oxides

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from the inherent strong electron correlations that reside within them. These materials can also possess electronic phase separation in which regions of vastly different resistive and magnetic behavior can coexist within a single crystal alloy material. By reducing the scale of these materials to length scales at and below the inherent size of the electronic domains, novel behaviors can be exposed. Because of this and the fact that spin-charge-lattice-orbital order parameters each involve correlation lengths, spatially reducing these materials for transport measurements is a critical step in understanding the fundamental physics that drives complex behaviors. These materials also offer great potential to become the next generation of electronic devices 1-3. Thus, the fabrication of low dimensional nano- or micro-structures is extremely important to achieve new functionality. This involves multiple controllable processes from high quality thin film growth to accurate electronic property characterization. Here, we present fabrication protocols of high quality microstructures for complex oxide manganite devices. Detailed descriptions and required equipment of thin film growth, photo-lithography, and wire-bonding are presented.

We describe the use of pulsed laser deposition (PLD), photolithography and wire-bonding techniques to create micrometer scale complex oxides devices. The PLD is utilized to grow epitaxial thin films. Photolithography and wire-bonding techniques are introduced to create practical devices for measurement purposes.

空间密闭的复合氧化物制备

Complex materials such as high Tc superconductors, multiferroics, and colossal magnetoresistors have electronic and magnetic properties that arise from ...

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 ...

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

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

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

对于新材料的低温磁输运测量先进的实验方法

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

Epitaxial Growth of Perovskite Strontium Titanate on Germanium via Atomic Layer Deposition

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and conformality by taking advantage of self-limiting reactions between vapor-phase precursors and the growing film. Perovskite oxides present potential for next-generation electronic materials, but to-date have mostly been deposited by physical methods. This work outlines a method for depositing SrTiO3 (STO) on germanium using ALD. Germanium has higher carrier mobilities than silicon and therefore offers an alternative semiconductor material with faster device operation. This method takes advantage of the instability of germanium's native oxide by using thermal deoxidation to clean and reconstruct the Ge (001) surface to the 2&#215;1 structure. 2-nm thick, amorphous STO is then deposited by ALD. The STO film is annealed under ultra-high vacuum and crystallizes on the reconstructed Ge surface. Reflection high-energy electron diffraction (RHEED) is used during this annealing step to monitor the STO crystallization. The thin, crystalline layer of STO acts as a template for subsequent growth of STO that is crystalline as-grown, as confirmed by RHEED. In situ X-ray photoelectron spectroscopy is used to verify film stoichiometry before and after the annealing step, as well as after subsequent STO growth. This procedure provides framework for additional perovskite oxides to be deposited on semiconductors via chemical methods in addition to the integration of more sophisticated heterostructures already achievable by physical methods.

This work details the procedures for the growth and characterization of crystalline SrTiO3 directly on germanium substrates by atomic layer deposition. The procedure illustrates the ability of an all-chemical growth method to integrate oxides monolithically onto semiconductors for metal-oxide semiconductor devices.

锗通过原子层沉积钙钛矿型钛酸锶的外延生长

Atomic layer deposition (ALD) is a commercially utilized deposition method for electronic materials. ALD growth of thin films offers thickness control and ...

Fabrication of Flexible Image Sensor Based on Lateral NIPIN Phototransistors

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, but several challenging points remain, such as a low absorption efficiency due to a thin active layer and low flexibility. We present an advanced method to fabricate a flexible phototransistor array with an improved electrical performance. The outstanding electrical performance is driven by a low dark current owing to deep impurity doping. Stretchable and flexible metal interconnectors simultaneously offer electrical and mechanical stabilities in a highly deformed state. The protocol explicitly describes the fabrication process of the phototransistor using a thin silicon membrane. By measuring I-V characteristics of the completed device in deformed states, we demonstrate that this approach improves the mechanical and electrical stabilities of the phototransistor array. We expect that this approach to a flexible phototransistor can be widely used for the applications of not only next-generation imaging systems/optoelectronics but also wearable devices such as tactile/pressure/temperature sensors and health monitors.

We present a detailed method to fabricate a deformable lateral NIPIN phototransistor array for curved image sensors. The phototransistor array with an open mesh form, which is composed of thin silicon islands and stretchable metal interconnectors, provides flexibility and stretchability. The parameter analyzer characterizes the electrical property of the fabricated phototransistor.

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

Flexible photodetectors have been intensely studied for the use of curved image sensors, which are a crucial component in bio-inspired imaging systems, ...

Bulk and Thin Film Synthesis of Compositionally Variant Entropy-stabilized Oxides

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (Cu variant) entropy-stabilized oxides. Phase pure and chemically homogeneous (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (x = 0.20, 0.27, 0.33) and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O (x = 0.11, 0.27) ceramic pellets are synthesized and used in the deposition of ultra-high quality, phase pure, single crystalline thin films of the target stoichiometry. A detailed methodology for the deposition of smooth, chemically homogeneous, entropy-stabilized oxide thin films by pulsed laser deposition on (001)-oriented MgO substrates is described. The phase and crystallinity of bulk and thin film materials are confirmed using X-ray diffraction. Composition and chemical homogeneity are confirmed by X-ray photoelectron spectroscopy and energy dispersive X-ray spectroscopy. The surface topography of thin films is measured with scanning probe microscopy. The synthesis of high quality, single crystalline, entropy-stabilized oxide thin films enables the study of interface, size, strain, and disorder effects on the properties in this new class of highly disordered oxide materials.

The synthesis of high quality bulk and thin film (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O and (Mg0.25(1-x)Co0.25(1-x)Ni0.25(1-x)CuxZn0.25(1-x))O entropy-stabilized oxides is presented.

组分变熵稳定氧化物的体积和薄膜合成

Here, we present a procedure for the synthesis of bulk and thin film multicomponent (Mg0.25(1-x)CoxNi0.25(1-x)Cu0.25(1-x)Zn0.25(1-x))O (Co variant) and ...

A Standard and Reliable Method to Fabricate Two-Dimensional Nanoelectronics

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D materials is still in nascent stages, scientists cannot fully rely on traditional semiconductor techniques for related research. Delicate processes from locating the materials to electrode definition need to be well controlled. In this article, a universal fabrication protocol required in manufacturing nanoscale electronics, such as 2D quasi-heterojunction bipolar transistors (Q-HBT), and 2D back-gated transistors are demonstrated. This protocol includes the determination of material position, electron beam lithography (EBL), metal electrode definition, et al. A step by step narrative of the fabrication procedures for these devices are also presented. Furthermore, results show that each of the fabricated devices has achieved high performance with high repeatability. This work reveals a comprehensive description of process flow for preparing 2D nano-electronics, enables the research groups to access this information, and pave the way toward future electronics.

The article aims to introduce a standard and reliable fabrication procedure for the development of future low dimensional nanoelectronics.

制造二维电子学的标准可靠方法

Two-dimensional (2D) materials have attracted huge attention due to their unique properties and potential applications. Since wafer scale synthesis of 2D ...

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 ...

Fabricating van der Waals Heterostructures with Precise Rotational Alignment

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We demonstrate not only lateral control but, importantly, also control over the angular alignment of adjacent layers. The core of the technique is represented by a home-built transfer setup which allows the user to control the position of the individual crystals involved in the transfer. This is achieved with sub-micrometer (translational) and sub-degree (angular) precision. Prior to stacking them together, the isolated crystals are individually manipulated by custom-designed moving stages that are controlled by a programmed software interface. Moreover, since the entire transfer setup is computer controlled, the user can remotely create precise heterostructures without coming into direct contact with the transfer setup, labeling this technique as &#8220;hands-free&#8221;. In addition to presenting the transfer set-up, we also describe two techniques for preparing the crystals that are subsequently stacked.

In this work we describe a technique that is used to create new crystals (van der Waals heterostructures) by stacking ultrathin layered 2D materials with precise control over position and relative orientation.

使用精确旋转对齐来制造范德瓦尔斯异构结构

In this work we describe a technique for creating new crystals (van der Waals heterostructures) by stacking distinct ultrathin layered 2D materials. We ...

基于范德华 Heteroepitaxy 的柔性铁电元件制备及测量方法

摘要

探索更多视频

此视频中的章节

空间密闭的复合氧化物制备

变磁B2有序化的FeRh外延层溅射生长和表征

化学气相沉积的有机磁体，钒四氰

对于新材料的低温磁输运测量先进的实验方法

锗通过原子层沉积钙钛矿型钛酸锶的外延生长

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

组分变熵稳定氧化物的体积和薄膜合成

制造二维电子学的标准可靠方法

液晶中磁调谐铁电极化的测量

使用精确旋转对齐来制造范德瓦尔斯异构结构

基于范德华 Heteroepitaxy 的柔性铁电元件制备及测量方法

摘要

探索更多视频

此视频中的章节

空间密闭的复合氧化物制备

变磁B2有序化的FeRh外延层溅射生​​长和表征

化学气相沉积的有机磁体，钒四氰

对于新材料的低温磁输运测量先进的实验方法

锗通过原子层沉积钙钛矿型钛酸锶的外延生长

基于侧向 NIPIN Phototransistors 的柔性图像传感器的研制

组分变熵稳定氧化物的体积和薄膜合成

制造二维电子学的标准可靠方法

液晶中磁调谐铁电极化的测量

使用精确旋转对齐来制造范德瓦尔斯异构结构

变磁B2有序化的FeRh外延层溅射生长和表征