作者没有什么可透露的。

开始前请注意所有相关的材料安全数据表 (MSDS)。尽管该协议具有生态友好性, 但在相应的程序中使用了一些酸和氧化剂。此外, 使用所有适当的个人防护设备 (实验室大衣, 手套, 安全眼镜, 等 ). 
 1. 解决方案的准备 注意: 在解决方案包含的容器完全密封后, 在足够的时间内, 在室温下对所有溶液进行了强磁搅拌. 
<ol> <li> 高氯酸溶液的制备 <ol> <li> 将100毫升高氯酸 (HClO 4 , 60%) 与400毫升绝对乙醇 (C 2 H 5 OH, 100%) 在1到4的体积比. </li>
	</ol> </li> <li> 的制备铬酸溶液 <ol> <li> 溶解9.0 克铬氧化物 (cro 3 ) 和20.3 毫升磷酸 (H 3 PO 4 , 85%) 在479.7 毫升去离子 (直喷) 水中 (cro 3 : H 3 PO 4 = 0.18 m: 0.56 m) </li>
	</ol> </li> <li> 准备硫酸电解质 <ol> <li> 混合16.2 毫升硫酸 (H 2 所以 4 , 98%) 在983.8 毫升直喷水中导致摩尔浓度 0.3 m </li>
	</ol> </li> <li> 在 1 L 直喷水中制备草酸电解质 <ol> 27.012 克无水草酸 (C <li> 2 H 2 O 4 ), 导致摩尔浓度为 0.3 m 
	</ol> </li> </ol> 2。铝基板预处理 <ol> <li> 加工 al 试样 <ol> 将纯化的 al 试样 (和 #62; 99.99% 纯) 切成长方形方形状 (宽度 x 高度 x 厚度 = 20.0 mm x 50.0 mm x 1.0 mm), 所有的直角所述相邻曲面, 称为和 #34; 衬底和 #34; 以后. </li>
		<li> 抛光 multi-surfaces 的铝基板机械使用砂纸与适当的 ISO/FEPA 砂砾指定编号超过 P1000. 
		注: 有关详细信息, 请参阅 补充信息 . </li>
	</ol> </li> <li> 在 Al 基板的 multi-surfaces 上同时抛光 <ol> <li> 将大约350毫升的高氯酸乙醇溶液倒入双层夹克烧杯中, 最大容量为600毫升。然后, 将4/5 的铝基板浸入高氯酸溶液中. </li>
		<li> 将高氯酸溶液的温度设置为7和 #177; 0.1 和 #176; C 使用连接到双层护套烧杯的浴环行器. </li>
		<li> 在丙酮中通过超声波清洗 al 底物30-40 分钟, 用丙酮和 D 冲洗. 我用水几次, 以去除铝基板表面的有机残留物. </li>
		<li> 使用气枪或氮气 (N 2 ) 对铝基体进行干燥, 以消除残余溶剂的气体冲击. 
		注意: 不建议在大气环境下自然干燥, 因为溶剂的痕迹会对抛光的影响产生不利的影响. </li>
		<li> 将铝基板工作电极 (w) 连接到正极 (+) 端口和铂 (Pt) 线计数器电极 (.) 到可编程直流电源的负极 (-) 端口, 使用鳄鱼夹。铝基板和 Pt 线应相互平行 (请参见 图 S2 ). </li>
		<li> 对于 Pt., 平均适用于 2-4 min, 对 Al w 施加 +20.0 伏的前向偏差。根据表面条件, 如污染或粗糙度, 申请时间可保持在5分钟. 检查所有浸入溶液中的表面, 检查表面残留物是否脱落并滑入溶液。在这一步, 不建议磁搅拌, 因为检查是困难的搅拌下, 解决方案流可能会影响抛光的效果. 
		注意: 不要 electropolish 超过5分钟, 这可能会使表面退化. 
		选项: 通过 PC 接口记录 current-time ( I - t ) 特性行为有助于监视抛光程序 (如果存在异常点). </li>
		<li> 停止应用偏倚并断开鳄鱼夹。从抛光溶液中仔细取铝基体和 Pt 电极。然后, 用乙醇 (95%) 和 D. 水来除去铝基板表面的残余溶液。如果抛光的执行正确, 可以识别铝基板的类似镜面的成品表面 (请参见 图 S1 和 图 S3 )。
		<li> 将 electropolished 铝基板储存在乙醇 (95%) 中, 直到下一道工序减少表面氧化. </li>
	</ol> </li> </ol> 3。草酸电解质下 AAOs 的大量制备 注意: 对于 AAOs 的纳米和 #39 的长程安排; 周期性, two-step SMSAs 程序被使用, 其中周期性纹理铝 multi-surfaces通过预 SMSA, 然后, 主要 SMSA 进行了制作高素质的 AAOs。重复应用的单位序列可以保持生产的复数和几乎相同的 AAOs, 直到铝基板保持。和 #34; n 和 #34; 表示应用的序列的编号. 
<ol> <li> n th 前 SMSA <ol> <li> 将大约650毫升的草酸水溶液倒入0.3 米的摩尔浓度为双套式烧杯, 最大能力为1.0 升。然后, 将约三季度的铝基板浸入草酸溶液中. </li>
		<li> 将草酸电解液的温度设置为15和 #177; 0.1 和 #176; C 使用连接到双层护套烧杯的浴环行器. </li>
		<li> 从乙醇中提取 electropolished 铝基板, 并使用气枪或 N 2 气体吹除残余溶剂. </li>
		<li> 使用鳄鱼夹将 electropolished 铝衬底与 w (+) 和 Pt 线连接到可编程直流电源的. (-)。铝基板和 Pt 导线应相互平行。然后, 将铝基板的 electropolished 部分浸入草酸电解质中. 
		注意: 要确保在酸性电解质的顶部和连接到 Al 衬底的鳄鱼夹底部之间存在足够的空间 ( 例如 , 大约1厘米), 否则在鳄鱼夹连接的位置会发生严重的腐蚀. </li>
		<li> 在 100-150 rpm 的适度磁性搅拌下, 在保持电解质温度的情况下, 将 +40.0 V 至 w 的阳极偏差应用于., 超过1-2 小时. 
		注意: 如果前 SMSA 时间太短, multi-surfaces 的铝基板将不会被正确地纹理. 
		选项: 通过 PC 接口记录 I - t 特性行为有助于理解 SMSA 中的典型行为。
		<li> 停止应用阳极偏置 af完成前 SMSA, 并断开鳄鱼剪辑。从酸性电解质中仔细提取样品, 用丙酮和 D 冲洗前 SMSAed 铝基板. 我喝水过几次. </li>
	</ol> </li> <li> n 前 AAOs 蚀刻 <ol> 将铬酸水溶液的温度设置为 60-#160; 65 和 #176; C. <li>
		<li> 将预 SMSAed 铝基板浸入 1 #160 的铬酸溶液中; 2 h 以去除铝基板上的预 AAOs. </li>
		<li> 用丙酮和直喷水冲洗前 AAOs 去除的铝基板几次。测量 Al 衬底的电阻, 以确定 AAOs 是否已在表面上完全移除。如果没有, 重复蚀刻程序 (步骤 3.2.2). </li>
	</ol> </li> <li> n th 主-SMSA <ol> <li> 将所有实验条件和连接都重新设置为步骤3.1 中使用的情况. 
		注: 应注意的是, 草酸电解质可以在几个序列中使用, 这不会影响主 AAOs 的质量。然而, 为了定量比较, 建议使用电解质在一个整体序列, 然后交换与一个新的. </li>
		<li> 对. 应用 +40.0 V 至 w 的阳极偏差; 适用时间可根据所需的阳极氧化铝厚度而变化。阳极氧化铝的生长率估计为8.0 和 7.5, #956; 在铝基板的前后表面, 在15和 #176 的电解质温度下, 分别为 (参考 57 ). </li>
	</ol> </li> <li> n srb-剥离 <ol> 停止应用阳极偏置并在完成主 SMSA 后搅拌, 并将主-SMSAed 铝基板与. (-) 和 Pt 线连接到可编程 DC 的 w (+)通过切换每个鳄鱼夹子来供电. </li>
		<li> 应用 srb, 并检查典型的起泡效果沿 multi-edges 的铝基板覆盖的主-AAOs。srb 条件的详细情况, 如开始 RB 的强度, 楼梯的数量, 以及每个台阶的持续时间, 都与主-AAOs 的厚度紧密相关。对于主-AAOs 厚度大于60和 #956; m, srb 的台阶由-21 v 到-24 v 控制, 增量-1 v 并且没有时间间隔在毗邻台阶之间。-21 v、-22 v 和-23 v 的持续时间固定在10分钟, 并且在分离过程完成之前保持-24 v 的最后一个台阶 (有关详细信息, 请参阅参考 57 , 以了解更详细的情况, 包括 AAOs). 
		注意: 强烈建议初学者使用 srb 的 PC 接口控制, 并在此过程中记录 I - t 特征曲线. </li>
		<li> 完成剥离后停止应用 srb, 并断开鳄鱼夹。从酸性电解液中仔细拿起样品, 用丙酮和 D 仔细冲洗. 我的水有足够的次数. </li>
		<li> 完全从相应的 Al 表面分离每个阳极氧化铝。在步3.4.3 之后, 分离的 AAOs 的上部部分仍然连接到 Al 基体, 应该手工地打破. </li>
	</ol> </li> <li> n 残余氧化铝蚀刻 <ol> <li> 将铬酸溶液的温度设置为60-65 和 #176; C, 将 AAOs 分离的铝基板浸泡约30分钟, 以消除残余氧化铝. </li>
		<li> 拿起蚀刻铝基体, 用丙酮和直喷水冲洗几次。测量电阻以确认残余氧化铝的完全去除。如果没有, 请重复步骤 3.5.2. </li>
	</ol> </li> <li> n+1 th 序列 <ol> <li> 进入步骤 3.1, 并使用剩余的氧化铝蚀刻铝基板重复整个序列. </li>
	</ol> </li> </ol> 4。硫酸电解质 AAOs 的大量制备 注意: 在本节中, 明确指出了步骤3中的不同条件. 
<ol> <li> n 第 前 SMSA <ol> <li> 将大约650毫升的硫酸水溶液 (0.3 米) 倒入双层套式烧杯中, 最大容量为1.0 升。然后, 约三季度的铝基板浸入硫酸溶液中. </li>
		<li> 设置0和 #177 的电解液温度; 0.1 和 #176; C. </li>
		<li> 使用气枪或 N 2 气体吹除 electropolished 铝基板上的残余溶剂, 并使用鳄鱼夹子将 Al 衬底连接到可编程直流电源 (请参阅步骤 3.1.4) </li>
		<li> 在中等磁性搅拌 (100-150 rpm) 下, 对. 施加超过 1-2 h 的 +25.0 V 至 w 的阳极偏差. </li>
		<li> 在完成预 SMSA 后停止应用阳极偏差, 并断开鳄鱼夹。用丙酮和 D 冲洗前 SMSAed 铝基板. 我喝水过几次. 
		注意: 对于 n th 前 AAOs 蚀刻, 请参阅步骤 3.2. </li>
	</ol> </li> <li> n th 主-SMSA <ol> <li> 将所有实验条件和连接都重新设置为步骤4.1 中使用的情况. </li>
		<li> 应用相同的阳极偏差。应用时间可根据需要的氧化铝厚度而变化。阳极氧化铝的生长率估计为5.3 和 #956; m/小时 (参见参考 56 以了解更多详细信息). </li>
	</ol> </li> <li> n srb-剥离 <ol> 在完成主 SMSA 后停止应用阳极偏置和搅拌, 并将主-SMSAed 铝基板与. (-) 和 Pt 线连接到可编程直流电源的 w (+)通过切换每个鳄鱼夹子提供. </li>
		<li> 应用 srb, 并检查典型的冒泡效果和样品的 multi-edges。台阶在 srb 被控制从-15 v 到-17 v 以增量-1 v 并且没有时间间隔在毗邻台阶之间。-15 v 和-16 v 的持续时间固定在10分钟, 并且在分离过程完成之前保持-17 v 的最后台阶. 
		注: 基于在硫酸电解质下制备的 AAOs 更脆的性质, 在分离时刻, 伴随着明显的咔嗒声, 电流水平突然增加. </li>
		<li> 停止应用 srb 后完成剥离, 并断开鳄鱼剪辑。从酸性电解液中仔细拿起样品, 用丙酮和 D 仔细冲洗. 我的水有足够的次数. </li>
		<li> 通过断开分离的 AAOs 的上部, 机械地将每个阳极氧化铝从相应的 Al 表面分离出来. 
		注: 对于 n th 剩余氧化铝蚀刻参考步骤 3.5. </li>
	</ol> </li> <li> n+1 th 序列 <ol> <li> 进入步骤 4.1, 并使用剩余的氧化铝蚀刻铝基板重复整个序列. </li>
	</ol>
	</li>
</ol>

这项研究得到了韩国国家研究基金会 (NRF) 资助的韩国政府 (MSIP) (No. 2016R1C1B1016344 和 2016R1E1A2915664) 的部分支持。

在本文中, 我们成功地展示了一种简便、高产、环保的方法, 通过 SMSA 和 srb 分离制备纳米多孔 AAOs, 可以重复到相同的铝基板, 从而显著提高质量性以及有限的天然资源的可用性。如图 1a的流程图所示, 我们的氧化铝制造策略是基于传统的 two-step 阳极氧化, 在 multi-surfaces 情况下进行了修改。因为电场在抛光和 two-step SMSAs 规程在正常方向被形成了在 multi-surfaces, 电化学反应发生,...

在酸性电解质中由阳极氧化 Al 基体形成的 AAOs, 引起了对各种基础科学和工业的极大兴趣, 例如, 纳米管/纳米线的硬模板1,2,3,4,5, 能量存储设备6,7,8,9, 生物传感10,11, 过滤应用程序12,13,14, 用于蒸发和/或蚀刻的掩码15,16,17, 和电容式湿度传感器18,19,20,21 ,22, 由于其 self-ordered 蜂窝结构, 高宽比纳米, 和优异的机械性能23。为了将纳米多孔 AAOs 应用于这些不同的应用, 它们应该是具有高度和长程有序排列的纳米的独立形式。在这方面, 获得 AAOs 的战略必须考虑形成 (阳极氧化) 和分离 (剥离) 程序。
从阳极氧化铝的形成角度来看, 轻度阳极氧化 (以下简称 MA) 是在硫酸、草酸和磷酸电解质下很好地建立的23,24,25,26 ,27。然而, ma 过程展示了 low-yields 氧化铝制造由于他们的缓慢的成长率取决于相对地低强度的阳极电压, 将进一步恶化通过 two-step ma 过程改进纳米的周期性28 ,29。因此, 采用更高的阳极电压 (草酸/硫酸电解质) 或使用更浓的电解质 (磷酸)30,31, 将硬阳极化 (HA) 技术作为替代 MA 的方法. 32,33,34,3536373839HA 进程显示了不同的增长速率和周期性安排, 而结果 AAOs 变得更加脆弱, 而纳米的密度则降低了30。此外, 需要一个昂贵的冷却系统, 以驱散由高电流密度引起的焦耳的加热31。这些结果限制了 AAOs 通过 HA 过程的潜在适用性。
在铝板的相应表面分离出一个阳极氧化铝时, 在 MA 和 HA 过程中使用有毒化学物质, 如氯化铜35,39, 对剩余铝基板的选择性化学蚀刻得到了最广泛的应用. 、41、42或水银氯161743444547,48,49. 然而, 这种方法会产生不利的副作用,如: 如, 较长的反应时间与 Al 的剩余厚度成正比, 重金属离子对阳极氧化铝的污染, 对人体/自然环境的有害残留物。, 而且有价值的资源使用效率低下。因此, 许多试图实现直接剥离的阳极氧化铝。虽然两个阴极电压分层50,51和阳极电压脉冲剥离7,41,42,52, 53,54,55目前的优点是, 剩余的铝基板可以被重用, 前者的技术在化学蚀刻方法中需要几乎可比的时间50。尽管处理时间明显减少, 有害和高活性化学品, 例如二和/或高氯酸, 被用作分离电解质在后者的技术55, 其中一个额外的清洁由于阳极氧化和分离过程中电解质的变化, 需要进行工艺过程。特别是分离 AAOs 的分离行为和质量严重影响了其厚度。在具有相对较薄厚度的阳极氧化铝的情况下, 分离的一个可能含有裂纹和/或孔径。
上述所有试验方法都已应用于 Al 试样的 "单面", 不包括表面保护/工程用途, 而传统技术的这一特性也显示了氧化铝制造的关键局限性。在产量和加工方面, 这也影响了 AAOs56,57的潜在适用性。
为了满足日益增长的需求, 在氧化铝相关领域的轻便, 高产, 绿色技术的方法, 我们先前报告的 SMSA 和直接支队通过 srb 在硫酸56和草酸57酸电解质, 分别。这是一个众所周知的事实, 复数 AAOs 可以形成多表面的铝基板浸入酸性电解质。然而, srb, 一个关键的区别, 我们的方法, 使这些 AAOs 从相应的铝基板的 multi-surfaces 在相同的酸性电解质用于 SMSAs 指示 mass-production, 简单, 和绿色技术特征.我们想指出的是, SRBs-based 支队是 SMSAs56,57的复数 AAOs 的最佳策略, 并且与 AAOs57的相对较薄的厚度相比, 更有效。单面上的阴极分层 (即, 恒定反向偏置)f ">> 51。最后, 由 SMSAs 顺序组合而成的 SRBs-based 分离器的单元序列可以重复地应用到相同的 Al 衬底, 避免复杂的程序和有毒/活性化学品, 从而强化了我们战略, 并保证自然资源的有效利用。

<table border="0" cellpadding="0" cellspacing="0" width="850">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Sulfuric Acid &#62;98%</td>
			<td style="width:212px;">DUKSAN reagent</td>
			<td style="width:119px;">5950</td>
			<td style="width:167px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Oxalic Acid Anhydrous, 99.5-100.2%</td>
			<td style="width:212px;">KANTO chemical</td>
			<td style="width:119px;">31045-73</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Phosphoric Acid, 85%</td>
			<td style="width:212px;">SAMCHUN chemical</td>
			<td style="width:119px;">P0463</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Perchloric Acid, 60%</td>
			<td style="width:212px;">SAMCHUN chemical</td>
			<td style="width:119px;">P0181</td>
			<td>Highly Reactive</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Chromium(VI) Oxide</td>
			<td style="width:212px;">Sigma Aldrich</td>
			<td style="width:119px;">232653</td>
			<td>Strong Oxidizer</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Ethanol, 95%</td>
			<td style="width:212px;">SAMCHUN chemical</td>
			<td style="width:119px;">E0219</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Absolute Ethanol, 99.9%</td>
			<td style="width:212px;">SAMCHUN chemical</td>
			<td style="width:119px;">E1320</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Double Jacket Beaker</td>
			<td style="width:212px;">iNexus</td>
			<td style="width:119px;">27-00292-05</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Low Temperature Bath Circulator</td>
			<td style="width:212px;">JEIO TECH</td>
			<td style="width:119px;">AAH57052K</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Programmable DC Power Supply</td>
			<td style="width:212px;">PNCYS</td>
			<td style="width:119px;">EDP-3001&#160;</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Aluminum Plate, &#62;99.99%</td>
			<td style="width:212px;">Goodfellow</td>
			<td style="width:119px;"></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Platinum Cylinder</td>
			<td style="width:212px;">Whatman</td>
			<td style="width:119px;">444685</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:352px;">Pure &#38; Ultra Pure Water System (Deionized Water)</td>
			<td style="width:212px;">Human Science</td>
			<td style="width:119px;">Pwer II &#38; HIQ II</td>
			<td></td>
		</tr>
	</tbody>
</table>

simultaneous multi-surface anodizations and stair-like reverse biases detachment of anodic aluminum oxides in sulfuric and oxalic acid electrolyte

在报告了 two-step 阳极氧化后, 纳米多孔阳极氧化铝 (AAOs) 在基础科学和工业应用领域得到广泛的利用, 因为它们的纳米周期排列相对较高纵横比。然而, 迄今为止所报告的技术, 这可能只适用于单表面阳极氧化, 显示严重的缺点,即, 耗时, 以及复杂的程序, 需要有毒化学品, 浪费宝贵的自然资源.本文介绍了一种简便、高效、环保的制备硫酸和草酸电解质纳米 AAOs 的方法, 克服了传统的氧化铝制备方法的局限性。首先, 通过同时 multi-surfaces 阳极氧化 (SMSA) 同时产生复数 AAOs, 表明 AAOs 具有可比性质的质量性。其次, 这些 AAOs 可以与铝 (铝) 基板分离, 在相同的电解质中应用楼梯样的反向偏置 (srb), 这意味着简单和绿色技术特性。最后, 将 SMSAs 连续组合与 SRBs-based 剥离的单元序列重复应用于同一 Al 衬底, 从而强化了该策略的优点, 同时保证了自然资源的有效利用。

nth的流程图主要由 two-step SMSAs、srb 剥离和相关化学蚀刻组成, 在图 1a中作了概要介绍。每个插图显示一个扫描电子显微镜 (SEM) 图像的对应的表面形貌在每个单独的程序和一张照片后立即采取 srb-支队。在单元序列的总 5th重复之后的示意图说明显示了 SMSA 和 SRBs-based 策略的优点 (图 1b)。分别在<strong class="xf...

Watch this Scientific Journal Video about Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte at JoVE.com

Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte

阳极氧化铝在硫酸和草酸电解质中的同时多表面 Anodizations 和阶梯式反向偏置剥离

提出了一种通过同时 multi-surfaces 阳极氧化制备多孔阳极氧化铝的协议, 并给出了阶梯式反向偏置分遣队。它可以反复应用于相同的铝基板, 表现出轻便、高产、环保的战略。

After reporting on the two-step anodization, nanoporous anodic aluminum oxides (AAOs) have been widely utilized in the versatile fields of fundamental ...

simultaneous-multi-surface-anodizations-stair-like-reverse-biases

Research

JoVE Journal

Engineering

7.2K 次观看.  Sungkyunkwan University. 提出了一种通过同时 multi-surfaces 阳极氧化制备多孔阳极氧化铝的协议, 并给出了阶梯式反向偏置分遣队。它可以反复应用于相同的铝基板, 表现出轻便、高产、环保的战略。

视频: Simultaneous Multi-surface Anodizations and Stair-like Reverse Biases Detachment of Anodic Aluminum Oxides in Sulfuric and Oxalic Acid Electrolyte

Fabrication of Nano-engineered Transparent Conducting Oxides by Pulsed Laser Deposition

Nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas allows the deposition of metal oxides with tunable morphology, structure, density and stoichiometry by a proper control of the plasma plume expansion dynamics. Such versatility can be exploited to produce nanostructured films from compact and dense to nanoporous characterized by a hierarchical assembly of nano-sized clusters. In particular we describe the detailed methodology to fabricate two types of Al-doped ZnO (AZO) films as transparent electrodes in photovoltaic devices: 1) at low O2 pressure, compact films with electrical conductivity and optical transparency close to the state of the art transparent conducting oxides (TCO) can be deposited at room temperature, to be compatible with thermally sensitive materials such as polymers used in organic photovoltaics (OPVs); 2) highly light scattering hierarchical structures resembling a forest of nano-trees are produced at higher pressures. Such structures show high Haze factor (&gt;80%) and may be exploited to enhance the light trapping capability. The method here described for AZO films can be applied to other metal oxides relevant for technological applications such as TiO2, Al2O3, WO3 and Ag4O4.

We describe the experimental method to deposit nanostructured oxide thin films by nanosecond Pulsed Laser Deposition (PLD) in the presence of a background gas. By using this method Al-doped ZnO (AZO) films, from compact to hierarchically structured as nano-tree forests, can be deposited.

制备纳米设计的脉冲激光沉积透明导电氧化物

Nanosecond Pulsed  Laser Deposition (PLD) in the presence of a background gas allows the deposition  of metal oxides with tunable morphology, structure, ...

科研

工程学

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 ...

Casting Protocols for the Production of Open Cell Aluminum Foams by the Replication Technique and the Effect on Porosity

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many cases validated experimentally, for light weight or impact energy absorbing structures, as high surface area heat exchangers or electrodes, as implants to the body, and many more. Although great progress has been made in understanding their structure-properties relationships, the large number of different processing techniques, each producing material with different characteristics and structure, means that understanding of the individual effects of all aspects of structure is not complete. The replication process, where molten metal is infiltrated between grains of a removable preform material, allows a markedly high degree of control and has been used to good effect to elucidate some of these relationships. Nevertheless, the process has many steps that are dependent on individual &#8220;know-how&#8221;, and this paper aims to provide a detailed description of all stages of one embodiment of this processing method, using materials and equipment that would be relatively easy to set up in a research environment. The goal of this protocol and its variants is to produce metal foams in an effective and simple way, giving the possibility to tailor the outcome of the samples by modifying certain steps within the process. By following this, open cell aluminum foams with pore sizes of 1&#8211;2.36 mm diameter and 61% to 77% porosity can be obtained.

Replication is one of the processing techniques used for the production of porous metal sponges. In this paper one implementation of the method for the production of open celled porous aluminum is shown in detail.

铸造协议的开孔泡沫铝通过复制技术的生产和孔隙率的影响

Metal foams are interesting materials from both a fundamental understanding and practical applications point of view. Uses have been proposed, and in many ...

Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures

Tetraiodine nonoxide (I4O9) has been synthesized using a dry approach that combines elemental oxygen and iodine without the introduction of hydrated species. The synthesis approach inhibits the topochemical effect promoting rapid hydration when exposed to the relative humidity of ambient air. This stable, amorphous, nano-particle material was analyzed using differential scanning calorimetry (DSC) and thermal gravimetric analysis (TGA) and showed an exothermic energy release at low temperature (i.e., 180 &#176;C) for the transformation of I4O9 into I2O5. This additional exothermic energy release contributes to an increase in overall reactivity of I4O9 when dry mixed with nano-aluminum (Al) powder, resulting in a minimum of 150% increase in flame speed compared to Al + I2O5. This study shows that as an oxidizer, I4O9 has more reactive potential than other forms of iodine(V) oxide when combined with Al, especially if I4O9 can be passivated to inhibit absorption of water from its surrounding environment.

Reaction Kinetics and Combustion Dynamics of I4O9 and Aluminum Mixtures

A protocol for measuring flame speeds of a reactive mixture composed of tetraiodine nonoxide (I4O9) and aluminum (Al) is presented. A method for resolving reaction kinetics using differential scanning calorimetry (DSC) is also presented. It was found that I4O9 is 150% more reactive than other iodine(V) oxides.

反应动力学和我燃烧动力学<sub&gt; 4</sub&gt; 0<sub&gt; 9</sub&gt;和铝的混合物

Tetraiodine nonoxide (I4O9) has been synthesized using a dry approach that combines elemental oxygen and iodine without the introduction of hydrated ...

Experimental Procedure for Warm Spinning of Cast Aluminum Components

High performance, cast aluminum automotive wheels are increasingly being incrementally formed via flow forming/metal spinning at elevated temperatures to improve material properties. With a wide array of processing parameters which can affect both the shape attained and resulting material properties, this type of processing is notoriously difficult to commission. A simplified, light-duty version of the process has been designed and implemented for full-size automotive wheels. The apparatus is intended to assist in understanding the deformation mechanisms and the material response to this type of processing. An experimental protocol has been developed to prepare for, and subsequently perform forming trials and is described for as-cast A356 wheel blanks. The thermal profile attained, along with instrumentation details are provided. Similitude with full-scale forming operations which impart significantly more deformation at faster rates is discussed.

An experimental protocol for instrumented warm rotary forming of cast aluminum alloys employing a bespoke industrially scaled apparatus is presented. Experimental considerations including thermal and mechanical effects are discussed, as well as similitude with full-scale processing of automotive wheels.

铸铝零部件的暖纺纱实验程序

High performance, cast aluminum automotive wheels are increasingly being incrementally formed via flow forming/metal spinning at elevated temperatures to ...

Dielectric RheoSANS &#8212; Simultaneous Interrogation of Impedance, Rheology and Small Angle Neutron Scattering of Complex Fluids

A procedure for the operation of a new dielectric RheoSANS instrument capable of simultaneous interrogation of the electrical, mechanical and microstructural properties of complex fluids is presented. The instrument consists of a Couette geometry contained within a modified forced convection oven mounted on a commercial rheometer. This instrument is available for use on the small angle neutron scattering (SANS) beamlines at the National Institute of Standards and Technology (NIST) Center for Neutron Research (NCNR). The Couette geometry is machined to be transparent to neutrons and provides for measurement of the electrical properties and microstructural properties of a sample confined between titanium cylinders while the sample undergoes arbitrary deformation. Synchronization of these measurements is enabled through the use of a customizable program that monitors and controls the execution of predetermined experimental protocols. Described here is a protocol to perform a flow sweep experiment where the shear rate is logarithmically stepped from a maximum value to a minimum value holding at each step for a specified period of time while frequency dependent dielectric measurements are made. Representative results are shown from a sample consisting of a gel composed of carbon black aggregates dispersed in propylene carbonate. As the gel undergoes steady shear, the carbon black network is mechanically deformed, which causes an initial decrease in conductivity associated with the breaking of bonds comprising the carbon black network. However, at higher shear rates, the conductivity recovers associated with the onset of shear thickening. Overall, these results demonstrate the utility of the simultaneous measurement of the rheo-electro-microstructural properties of these suspensions using the dielectric RheoSANS geometry.

Here, we present a procedure for the measurement of simultaneous impedance, rheology and neutron scattering from soft matter materials under shear flow.

介电RheoSANS  - 阻抗，流变性和复杂流体的小角中子散射的同时拷问

A procedure for the operation of a new dielectric RheoSANS instrument capable of simultaneous interrogation of the electrical, mechanical 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 ...

Enhanced Electron Injection and Exciton Confinement for Pure Blue Quantum-Dot Light-Emitting Diodes by Introducing Partially Oxidized Aluminum Cathode

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation displays and solid-state lighting technologies. The brightness and efficiency of blue QDs-based light-emitting diodes (LEDs) remain inferior to their red and green counterparts, due to the inherently unfavorable energy levels of different colors of light. To solve these problems, a device structure should be designed to balance the injection holes and electrons into the emissive QD layer. Herein, through a simple autoxidation strategy, pure blue QD-LEDs which are highly bright and efficient are demonstrated, with a structure of ITO/PEDOT:PSS/Poly-TPD/QDs/Al:Al2O3. The autoxidized Al:Al2O3 cathode can effectively balance the injected charges and enhance radiative recombination without introducing an additional electron transport layer (ETL). As a result, high color-saturated blue QD-LEDs are achieved with a maximum luminance over 13,000 cd m-2, and a maximum current efficiency of 1.15 cd A-1. The easily controlled autoxidation procedure paves the way for achieving high-performance blue QD-LEDs.

A protocol is presented for fabricating high-performance, pure blue ZnCdS/ZnS-based quantum dots light-emitting diodes by employing an autoxidized aluminum cathode.

采用部分氧化铝阴极增强电子注入和激子约束的纯蓝色量子点发光二极管

Stable and efficient red (R), green (G), and blue (B) light sources based on solution-processed quantum dots (QDs) play important roles in next-generation ...

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 ...

Generation and Control of Electrohydrodynamic Flows in Aqueous Electrolyte Solutions

To drive electrohydrodynamic (EHD) flows in aqueous solutions, the separation of cation and anion transport pathways is essential because a directed electric body force has to be induced by ionic motions in liquid. On the other hand, positive and negative charges attract each other, and electroneutrality is maintained everywhere in equilibrium conditions. Furthermore, an increase in an applied voltage has to be suppressed to avoid water electrolysis, which causes the solutions to become unstable. Usually, EHD flows can be induced in non-aqueous solutions by applying extremely high voltages, such as tens of kV, to inject electrical charges. In this study, two methods are introduced to generate EHD flows induced by electrical charge separations in aqueous solutions, where two liquid phases are separated by an ion-exchange membrane. Due to a difference in the ionic mobility in the membrane, ion concentration polarization is induced between both sides of the membrane. In this study, we demonstrate two methods. (i) The relaxation of ion concentration gradients occurs via a flow channel that penetrates an ion-exchange membrane, where the transport of the slower species in the membrane selectively becomes dominant in the flow channel. This is a driving force to generate an EHD flow in the liquid. (ii) A long waiting time for the diffusion of ions passing through the ion-exchange membrane enables the generation of an ion-dragged flow by externally applying an electric field. Ions concentrated in a flow channel of a 1 x 1 mm2 cross-section determine the direction of the liquid flow, corresponding to the electrophoretic transport pathways. In both methods, the electric voltage difference required for an EHD flow generation is drastically reduced to near 2 V by rectifying the ion transport pathways.

The rectification of ion transport pathways is an effective method to generate one-directional ion-dragged electrohydrodynamic flows. By setting an ion-exchange membrane in a flow channel, an electrically polarized condition is generated and causes a liquid flow to be driven when an electric field is externally applied.

水电解质溶液中 Electrohydrodynamic 流的产生与控制

To drive electrohydrodynamic (EHD) flows in aqueous solutions, the separation of cation and anion transport pathways is essential because a directed ...