作者愿意承认欧洲研究项目属于地平线2020研究和创新计划-3A 能源类柔性机器为新的加法和消减制造在下一代复杂3D金属零件

1. 粉末特性
<ol><li>将3克的启动 Ti-6Al-4V 粉末放在双面粘碳胶带上, 位于铝针存根上, 并插入场发射扫描电子显微镜 (FESEM) 的试样室内, 分析粉末16的形貌。</li>
	<li>通过填充30厘米3容器, 测量粉末的表观密度, 并根据 ASTM-B212 标准测量粉末的重量。</li>
	<li>通过元素 (例如、Leco) 和电感耦合等离子体 (ICP) 分析仪20, 对起始粉末 (5-10 克)、使用过的粉末 (5-10 克) 和沉积块 (17 克) 进行化学分析。</li>
</ol>2. 单轨道定向能量沉积
<ol><li>
粉末加载
	<ol>
<li>佩戴个人防护设备, 包括符合 EN 149 要求的 FFP3 呼吸面罩、无粉一次性丁腈橡胶手套和防护塑料眼镜。</li>
		<li>打开送粉系统的料斗, 并使用萃取风扇 (如, 防爆) 去除残余粉末。</li>
		<li>按照构造函数给出的适当指示, 拆卸料斗, 使用乙醇浸泡的纸巾清洁每个部件。 注意: 这一步是避免各种金属粉末污染的基础。</li>
		<li>按照构造函数给出的指令重新装配进料料斗。只留下料斗的顶盖, 以执行粉末的装载。</li>
		<li>在 50-150 µm 的范围内, 用 Ti-6Al-4V 粉末装载料斗, 颗粒. 根据可用料斗的大小, 请将其完全填满。</li>
		<li>关闭料斗顶盖非常紧密, 以避免任何气体泄漏。</li>
	</ol>
</li>
	<li>
样品的准备
	<ol>
<li>选择一个 Ti-6Al-4V 的表, 50 毫米 x 50 毫米尺寸和4毫米厚度。</li>
		<li>用乙醇浸泡过的纸巾清洁钛片表面。用百分制平衡测量工作表的重量。</li>
		<li>根据标记的位置将纸张放在工作区上。工作区域是进行沉积的地方, 因此根据机器人的编程路径确定。</li>
	</ol>
</li>
	<li>
机器人的制备及沉积设备的制备
	<ol>
<li>将喷嘴安装在激光头上, 使喷嘴轴与激光轴之间的夹角35°。</li>
		<li>将机器人移动到起始工作点以执行校准。</li>
		<li>检查喷嘴和工作平面之间的距离, 如果需要, 请手动更正喷嘴位置, 直到测量到的距离为5毫米。 注: 由于工作区域位于水平平面上, 此距离是金属片与喷嘴尖端之间的垂直距离。</li>
		<li>用激光检查喷嘴插座的中心点: 首先, 在激光控制的软件上点击 "激光引导器" 命令, 开关激光导轨。然后, 把一个细杆, 测量直径0.8 毫米, 长度为200毫米, 喷嘴内。验证杆的尖端和激光导轨的光斑是否重合。如果没有, 手动调整喷嘴的位置, 以尊重前面所指出的距离和角度。 注: 在这种情况下, 喷嘴外径为1毫米;如果采用较小直径的喷嘴, 则使用直径小于喷嘴的杆。</li>
		<li>验证写入机器人控制软件的校准数据: 单击软件上的 "应用" 按钮, 然后等待代码的编译。 注: 本软件将检查代码中的错误;如果未检测到错误, 则将代码存储在机器人控制器上。如果检测到错误, 则不会编译代码, 需要进行进一步的修订。</li>
		<li>通过单击激光控制软件上的 "激光启用" 命令, 启用激光源模块。 注: 所使用的激光源是连续光纤激光发射在红外线区域 (1064 毫微米) 与5千瓦最大功率。</li>
		<li>在机器人的控制柜上手动按下 "机器人马达" 按钮, 并检查相关的安全指示灯是否亮起: 如果是这样, 则表示电动机已启用。</li>
	</ol>
</li>
	<li>
开始沉积过程
	<ol>
<li>在现有程序列表中选择正确的文件, 并将工作路径加载到主机器人例程中。</li>
		<li>检查激光和机器人参数: 将激光功率设置为特定的激光功率 (325、650、980、1500 W) 和机器人速度到给定速度 (30、40、50、60毫米/秒)。 注: 根据机器的具体语言, 将这些参数写入机器人的控制软件中。</li>
		<li>通过在软件上按 "应用" 按钮来确认新参数, 并等待代码的编译。该软件将检查代码中的错误;如果检测不到错误, 则将代码存储在机器人控制器上, 并准备好启动。通过推动机器人控制软件上的 "启动" 按钮启动机器人程序。</li>
	</ol>
</li>
	<li>用特制的夹钳取样品, 用乙醇浸泡过的纸巾清洁样品表面, 除去残留的粉末。</li>
</ol>3. 分析单车道
<ol><li>用5X 放大的立体声显微镜从顶部分析单个轨道。 注意: 在这个阶段, 一些图像是采取了立体显微镜和视觉分析。</li>
	<li>使用精确的刀具, 从沉积轨迹的中间截去垂直于沉积方向的单线轨迹。</li>
	<li>在环氧树脂中安装单线的横断面。选择一个安装杯, 并放置在它的清洁和干燥标本。用重量 (10 克/样品) 仔细测量适量的树脂, 然后与液体固化剂 (6 克/样品) 混合。将树脂混合物倒在试样上, 在室温下将填充的安装杯放在30分钟内固化。此后, 研磨的安装标本与 500, 800, 1200 粒粒度碳化硅纸, 然后抛光使用钻石粘贴下, 以更精细的尺寸钻石颗粒 (1 µm)。</li>
	<li>用光学显微镜分析抛光表面的形状和孔隙度。以10X 倍放大的光学显微镜获取熔池的图像, 然后使用图像 J 软件对其进行分析。</li>
	<li>通过测量熔池顶部和底部之间的距离, 测量熔池的高度。然后, 将熔池的测量高度作为特定能量密度的函数进行绘制, 并根据相应的方程进行计算。实际上, 能量密度可以用以下等式计算: <img alt="Equation 1" src="/files/ftp_upload/56966/56966eq1.jpg">
</li>
	<li>在实验结果上拟合 2nd阶多项式, 得到与层厚度相对应的比能量密度函数的方程。</li>
	<li>考虑一个特定的能量密度, 并根据它们的关系计算层厚度, 在上一步中观察到。</li>
	<li>为了验证该方法, 通过考虑计算层厚度, 构造了多层块, 然后根据孔隙度和最终高度对区块截面进行了表征。</li>
	<li>在与3.3 节相同的过程中, 分析了抛光步骤后的加工块的显微结构。事实上, 在最终抛光后, 用92毫升蒸馏水、6毫升硝酸和2毫升氢氟酸的试剂蚀刻三十年代的样品。</li>
</ol>

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作者没有什么可透露的。

根据熔池特性的几何形状, 重点研究了 Ti-6Al-4V 过程中的切片厚度设置。为此, 定义并使用了两步协议。该协议的第一部分是对单扫描沉积过程参数的优化, 并在此步骤中实现了最佳参数, 并测量了熔池的几何形状。在该协议的第二部分, 计算了试样在最佳参数下的比能量密度。在此步骤中, 将熔池的高度绘制为能量密度函数, 在这一关键步骤中, 可以实现多层沉积层厚度。
由于?...

Ti-6Al-4V 是航空航天、飞机、汽车和生物医学行业中最常用的钛合金, 由于其高强度重量比、优异的断裂韧性、低比重、优异的耐腐蚀性和热可处理性.然而, 由于其导热系数低、反应性高, 因此其在其它应用方面的进一步发展具有挑战性, 导致其加工性能较差。此外, 由于切削过程中的热硬化现象, 必须进行特定的热处理1,2,3,4。
尽管如此, 添加剂制造 (AM) 技术显示了巨大的潜力, 作为新的制造技术, 可以降低价格和能耗, 并解决一些目前的挑战, 在制造 Ti-6Al-4V 合金。
添加剂制造技术被称为创新, 可以以逐层的方式制造近网形状组件。逐层添加剂制造方法, 将计算机辅助设计 (CAD) 模型切片成薄层, 然后逐层构建组件层, 是所有 AM 方法的基础。一般情况下, 金属材料的添加剂制造可分为四种不同的工艺: 粉床、粉料 (吹粉)、送丝和其他路线3、5、6。
定向能量沉积是一类的添加剂制造, 是一个吹粉过程, 从 CAD 文件中捏造出三维 (3D) 近净形状实体零件, 类似于其他 AM 方法。与其他技术相比, 其不仅可以作为一种制造方法, 而且还可作为高附加值零件的修复技术使用。在该过程中, 金属粉末或金属丝材料由载气或马达送入熔池, 由激光束在基体或先前沉积层上产生。该过程是一个有希望的先进制造工艺, 它能够降低购飞比, 并且能够修复以前成本高昂的高价值部件, 以取代或无法挽回的7。
为了实现所需的几何尺寸和材料属性, 建立适当的参数8至关重要。已进行了几项研究, 以阐明工艺参数与沉积样品的最终性质之间的关系。Peyre et 。9构建了一些具有不同工艺参数的薄壁壁, 然后使用2D 和3D 轮廓术对其进行了特征描述。结果表明, 层厚度和熔池体积对粗糙度参数有显著影响。Vim et al。10提出了一个模型, 以便分析单个包覆层 (包覆高度、复合宽度和穿透深度) 的工艺参数与几何特征之间的关系。
迄今为止, 关于 Ti 合金的若干研究报告, 其中大部分侧重于参数组合对大量样品的性能的影响11,12,4。Rasheedat et al。研究了扫描速度和粉流速率对激光金属沉积 Ti-6Al-4V 合金产生性能的影响。他们发现, 通过提高扫描速度和粉末流速, 显微组织从 Widmanstätten 转变为马氏体显微组织, 导致表面粗糙度和沉积试样的显微硬度增加7。然而, 在设计层厚度设置方面却较少受到重视。彩虹et al。研究了层厚度与工艺参数之间的相关性。他们发现, 当前高度和实际高度之间的主要误差来源是粉末质量流速和层厚度设置13。他们的研究没有正确地实现层厚度设置, 因为它们涉及厚和不准确的过程中的层厚度设置。阮et al。研究了激光扫描速度对恒定激光功率和送粉率的影响, 在14。提出了在特定加工条件下获得的层厚度设置的一些经验模型, 因此, 由于使用了特定的工艺参数15, 层厚度设置可能不精确。与以往的工作相比, 本文提出的层厚设置过程是一种快速的方法, 可以在不浪费时间和材料的情况下进行。
本文的主要工作重点是根据 Ti-6Al-4V 合金在最佳工艺参数下的单轨道特性, 开发一种快速测定层厚度的方法。在不浪费时间和材料的情况下, 采用最佳工艺参数确定层厚, 制造高密度 Ti-6Al-4V 块。

<table><tbody><tr><td>Ti-6Al-4V powder</td><td>Xi&amp;rsquo;Tianrui new material</td><td></td><td>As starting material</td></tr><tr><td>ISOMET precision cutter</td><td>Bohler</td><td></td><td>To cut the samples</td></tr><tr><td>Polishing machine</td><td>Presi</td><td></td><td>To polish the samples</td></tr><tr><td>EpoFix resin</td><td>Presi</td><td></td><td>To mount the samples</td></tr><tr><td>Diamond paste</td><td>Presi</td><td></td><td>For polishing</td></tr><tr><td>Optical Microscope</td><td>Leica</td><td></td><td>Microstructural observation</td></tr><tr><td>Field emission scanning electron microscope</td><td>Merlin-Zeiss</td><td></td><td>Microstructural observation</td></tr><tr><td>Stereo microscope</td><td>Leica</td><td></td><td></td></tr><tr><td>LEC1- CS444 ANALYSER</td><td>IncoTest</td><td></td><td>Chemical analysis</td></tr><tr><td>LEC3 - ELTRA OHN2000 ANALYSER</td><td>IncoTest</td><td></td><td>Chemical analysis</td></tr><tr><td>LEC2 - LECO TC436AR ANALYSER</td><td>IncoTest</td><td></td><td>Chemical analysis</td></tr><tr><td>ICP</td><td>IncoTest</td><td></td><td>Chemical analysis</td></tr><tr><td>IRB 4600</td><td>ABB</td><td></td><td>Antropomorphic robot</td></tr><tr><td>GTV PF</td><td>GTV</td><td></td><td>Powder feeding system</td></tr><tr><td>YW 52</td><td>Precitec</td><td></td><td>Laser head</td></tr><tr><td>Nozzles</td><td>IRIS</td><td></td><td>Nozzle for feeding powders</td></tr><tr><td>YLS 3000</td><td>IPG Photonics</td><td></td><td>Laser source</td></tr></tbody></table>

production of single tracks of ti-6al-4v by directed energy deposition to determine the layer thickness for multilayer deposition

定向能量沉积是一种添加剂制造技术, 它涉及用激光束将金属粉末注入粒子的熔池创建。一般来说, 这种技术是用来制造或修复不同的组件。在这种技术中, 最终的特征受到许多因素的影响。事实上, 在建筑构件的主要任务之一是优化的工艺参数 (如激光功率, 激光速度, 焦点,等等), 这通常是通过广泛的实验研究进行。然而, 这类实验是非常冗长和昂贵的。为此, 为了加速优化过程, 对基于熔池特征的方法进行了研究。事实上, 在这些实验中, Ti-6Al-4V 的单一轨道是由一个由激光功率和激光速度组合而成的过程所沉积。分析了单轨道的表面形貌和尺寸, 并对剖面进行抛光和蚀刻后, 对熔池的几何特性进行了评价。通过对熔池特性的检测, 可以获得有关最佳工艺参数选择的有用信息。这些实验正在扩展以描述具有多层的大块。事实上, 这篇手稿描述了如何能够快速确定的厚度为大规模沉积, 并避免超过或低于沉积根据计算的能量密度的最佳参数。除沉积物的过度或不足外, 时间和材料的节省是这种方法的另一个巨大的优势, 其中多层组件的沉积可以启动, 而无需任何参数优化的层厚度。

在实验研究中, 不规则 Ti-6Al-4V 粉末的平均大小为 50-150 µm, 表观密度为1.85 克/厘米3 , 被用作沉积材料 (图 1)。对粉末的化学分析证实, 在沉积过程前后, 粉末的氧、氮含量没有变化, 而在两种情况下, 氧含量均高于 Ti-6Al-4V 粉标准氧含量。添加剂制造 (< 0.13%)。然而, 在沉积后, 大块组分的氧和氮含量增加。
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Watch this Scientific Journal Video about Production of Single Tracks of Ti-6Al-4V by Directed Energy Deposition to Determine the Layer Thickness for Multilayer Deposition at JoVE.com

Production of Single Tracks of Ti-6Al-4V by Directed Energy Deposition to Determine the Layer Thickness for Multilayer Deposition

本文研究了一种基于熔池特性的快速方法, 用于估算定向能沉积 Ti-6Al-4V 组分的层厚度。

用定向能沉积法生产 Ti-6Al-4V 层厚度的单车道多层沉积

Directed Energy Deposition (DED), which is an additive manufacturing technique, involves the creation of a molten pool with a laser beam where metal ...

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Universidad de Cartagena UDEC

Research

JoVE Journal

Engineering

9.2K 次观看.  Politecnico di Torino. 本文研究了一种基于熔池特性的快速方法, 用于估算定向能沉积 Ti-6Al-4V 组分的层厚度。

视频: Production of Single Tracks of Ti-6Al-4V by Directed Energy Deposition to Determine the Layer Thickness for Multilayer Deposition

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

Nanofabrication of Gate-defined GaAs/AlGaAs Lateral Quantum Dots

A quantum computer is a computer composed of quantum bits (qubits) that takes advantage of quantum effects, such as superposition of states and entanglement, to solve certain problems exponentially faster than with the best known algorithms on a classical computer. Gate-defined lateral quantum dots on GaAs/AlGaAs are one of many avenues explored for the implementation of a qubit. When properly fabricated, such a device is able to trap a small number of electrons in a certain region of space. The spin states of these electrons can then be used to implement the logical 0 and 1 of the quantum bit. Given the nanometer scale of these quantum dots, cleanroom facilities offering specialized equipment- such as scanning electron microscopes and e-beam evaporators- are required for their fabrication. Great care must be taken throughout the fabrication process to maintain cleanliness of the sample surface and to avoid damaging the fragile gates of the structure. This paper presents the detailed fabrication protocol of gate-defined lateral quantum dots from the wafer to a working device. Characterization methods and representative results are also briefly discussed. Although this paper concentrates on double quantum dots, the fabrication process remains the same for single or triple dots or even arrays of quantum dots. Moreover, the protocol can be adapted to fabricate lateral quantum dots on other substrates, such as Si/SiGe.

This paper presents a detailed fabrication protocol for gate-defined semiconductor lateral quantum dots on gallium arsenide heterostructures. These nanoscale devices are used to trap few electrons for use as quantum bits in quantum information processing or for other mesoscopic experiments such as coherent conductance measurements.

纳米加工门定义的GaAs / AlGaAs多量子点横向

A quantum computer is a computer composed of quantum bits (qubits) that takes advantage of quantum effects, such as superposition of states and ...

Atomically Defined Templates for Epitaxial Growth of Complex Oxide Thin Films

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain such surfaces are described. The first approach is the preparation of single terminated perovskite SrTiO3 (001) and DyScO3 (110) substrates. Wet etching was used to selectively remove one of the two possible surface terminations, while an annealing step was used to increase the smoothness of the surface. The resulting single terminated surfaces allow for the heteroepitaxial growth of perovskite oxide thin films with high crystalline quality and well-defined interfaces between substrate and film. In the second approach, seed layers for epitaxial film growth on arbitrary substrates were created by Langmuir-Blodgett (LB) deposition of nanosheets. As model system Ca2Nb3O10- nanosheets were used, prepared by delamination of their layered parent compound HCa2Nb3O10. A key advantage of creating seed layers with nanosheets is that relatively expensive and size-limited single crystalline substrates can be replaced by virtually any substrate material.

Various procedures are outlined to prepare atomically defined templates for epitaxial growth of complex oxide thin films. Chemical treatments of single crystalline SrTiO3 (001) and DyScO3 (110) substrates were performed to obtain atomically smooth, single terminated surfaces. Ca2 Nb3 O10- nanosheets were used to create atomically defined templates on arbitrary substrates.

原子定义模板复合氧化物薄膜的外延生长

Atomically defined substrate surfaces are prerequisite for the epitaxial growth of complex oxide thin films. In this protocol, two approaches to obtain ...

化学

Formation of Thick Dense Yttrium Iron Garnet Films Using Aerosol Deposition

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% of the bulk. The primary advantage of AD is that the deposition takes place entirely at ambient temperature; thereby enabling film growth in material systems with disparate melting temperatures. This report describes in detail the processing steps for preparing the powder and for performing AD using the custom-built system. Representative characterization results are presented from scanning electron microscopy, profilometry, and ferromagnetic resonance for films grown in this system. As a representative overview of the capabilities of the system, focus is given to a sample produced following the described protocol and system setup. Results indicate that this system can successfully deposit 11 &#181;m thick yttrium iron garnet films that are &#160;&#62; 90% of the bulk density during a single 5 min deposition run. A discussion of methods to afford better control of the aerosol and particle selection for improved thickness and roughness variations in the film is provided.

This report describes the use of a custom-built system to perform aerosol deposition of thick films of yttrium iron garnet onto sapphire substrates at RT. The deposited films are characterized using scanning electron microscopy, profilometry, and ferromagnetic resonance to give a representative overview of the capabilities of the technique.

浓稠钇铁石榴石薄膜的形成使用气溶胶沉积

Aerosol deposition (AD) is a thick-film deposition process that can produce layers up to several hundred micrometers thick with densities greater than 95% ...

Atomically Traceable Nanostructure Fabrication

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process being used in order to maintain exquisite control over both feature size and feature density. Here, we demonstrate a method for tracking atomically resolved and controlled structures from initial template definition through final nanostructure metrology, opening up a pathway for top-down atomic control over nanofabrication. Hydrogen depassivation lithography is the first step of the nanoscale fabrication process followed by selective atomic layer deposition of up to 2.8 nm of titania to make a nanoscale etch mask. Contrast with the background is shown, indicating different mechanisms for growth on the desired patterns and on the H passivated background. The patterns are then transferred into the bulk using reactive ion etching to form 20 nm tall nanostructures with linewidths down to ~6 nm. To illustrate the limitations of this process, arrays of holes and lines are fabricated. The various nanofabrication process steps are performed at disparate locations, so process integration is discussed. Related issues are discussed including using fiducial marks for finding nanostructures on a macroscopic sample and protecting the chemically reactive patterned Si(100)-H surface against degradation due to atmospheric exposure.

We report a protocol for combining the atomic metrology of the Scanning Tunneling Microscope for surface patterning with selective Atomic Layer Deposition and Reactive Ion Etching. Using a robust process involving numerous atmospheric exposures and transport, 3D nanostructures with atomic metrology are fabricated.

原子纳米结构可追溯制造

Reducing the scale of etched nanostructures below the 10 nm range eventually will require an atomic scale understanding of the entire fabrication process ...

Fabrication of Low Temperature Carbon Nanotube Vertical Interconnects Compatible with Semiconductor Technology

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive thin-films. Due to the low growth temperature, the process allows integration with modern low-&#954; dielectrics and some flexible substrates. The process is compatible with standard semiconductor fabrication, and a method for the fabrication of electrical 4-point probe test structures for vertical interconnect test structures is presented. Using scanning electron microscopy the morphology of the CNT bundles is investigated, which demonstrates vertical alignment of the CNT and can be used to tune the CNT growth time. With Raman spectroscopy the crystallinity of the CNT is investigated. It was found that the CNT have many defects, due to the low growth temperature. The electrical current-voltage measurements of the test vertical interconnects displays a linear response, indicating good ohmic contact was achieved between the CNT bundle and the top and bottom metal electrodes. The obtained resistivities of the CNT bundle are among the average values in the literature, while a record-low CNT growth temperature was used.

A method for the growth of low temperature vertically-aligned carbon nanotubes, and the subsequent fabrication of vertical interconnect electrical test structures using semiconductor fabrication is presented.

低温碳纳米管垂直互连的制作兼容半导体技术

We demonstrate a method for the low temperature growth (350 &#176;C) of vertically-aligned carbon nanotubes (CNT) bundles on electrically conductive ...

Fabrication of Ultra-thin Color Films with Highly Absorbing Media Using Oblique Angle Deposition

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present an advanced method for fabricating ultra-thin color films with improved characteristics. The proposed process addresses several fabrication issues, including large area processing. Specifically, the protocol describes a process for fabricating ultra-thin color films using an electron beam evaporator for oblique angle deposition of germanium (Ge) and gold (Au) on silicon (Si) substrates.&#160; Film porosity produced by the oblique angle deposition induces color changes in the ultra-thin film. The degree of color change depends on factors such as deposition angle and film thickness. Fabricated samples of the ultra-thin color films showed improved color tunability and color purity. In addition, the measured reflectance of the fabricated samples was converted into chromatic values and analyzed in terms of color. Our ultra-thin film fabricating method is expected to be used for various ultra-thin film applications such as flexible color electrodes, thin film solar cells, and optical filters. Also, the process developed here for analyzing the color of the fabricated samples is broadly useful for studying various color structures.

We present a detailed method for fabricating ultra-thin color films with improved characteristics for optical coatings. The oblique angle deposition technique using an electron beam evaporator allows improved color tunability and purity. Fabricated films of Ge and Au on Si substrates were analyzed by reflectance measurements and color information conversion.

用斜角沉积法制备高吸收介质的超薄彩色薄膜

Ultra-thin film structures have been studied extensively for use as optical coatings, but performance and fabrication challenges remain.&#160; We present ...

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide electronics community. One of its hallmark features is the existence of a critical LAO thickness of 4 unit-cells (uc) for interfacial conductivity to emerge. Although electrostatic mechanisms have been proposed in the past to describe the existence of this critical thickness, the importance of chemical defects has been recently accentuated. Here, we describe the growth of metal/LAO/STO heterostructures in an ultra-high vacuum (UHV) cluster system combining pulsed laser deposition (to grow the LAO), magnetron sputtering (to grow the metal) and X-ray photoelectron spectroscopy (XPS). We study step by step the formation and evolution of the q2DES and the chemical interactions that occur between the metal and the LAO/STO. Additionally, magnetotransport experiments elucidate on the transport and electronic properties of the q2DES. This systematic work not only demonstrates a way to study the electrostatic and chemical interplay between the q2DES and its environment, but also unlocks the possibility to couple multifunctional capping layers with the rich physics observed in two-dimensional electron systems, allowing the fabrication of new types of devices.

Growth and Electrostatic/chemical Properties of Metal/LaAlO3/SrTiO3 Heterostructures

We fabricate metal/LaAlO3/SrTiO3 heterostructures using a combination of pulsed laser deposition and in situ magnetron sputtering. Through magnetotransport and in situ X-ray photoelectron spectroscopy experiments, we investigate the interplay between electrostatic and chemical phenomena of the quasi two-dimensional electron gas formed in this system.

金属/LaAlO 的生长和静电/化学性质3/SrTiO3异

The quasi 2D electron system (q2DES) that forms at the interface between LaAlO3 (LAO) and SrTiO3 (STO) has attracted much attention from the oxide ...

Atomic Layer Deposition of Vanadium Dioxide and a Temperature-dependent Optical Model

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with wafer-scale uniformity and angstrom level control of thickness, the method of atomic-layer deposition was chosen. This ALD process enables high-quality, low-temperature (&#8804;150 &#176;C) growth of ultrathin films (100-1000 &#197;) of VO2. For this demonstration, the VO2 films were grown on sapphire substrates. This low temperature growth technique produces mostly amorphous VO2 films. A subsequent anneal in an ultra-high vacuum chamber with a pressure of 7x10-4 Pa of ultra-high purity (99.999%) oxygen produced oriented, polycrystalline VO2 films. The crystallinity, phase, and strain of the VO2 were determined by Raman spectroscopy and X-ray diffraction, while the stoichiometry and impurity levels were determined by X-ray photoelectron spectroscopy, and finally the morphology was determined by atomic force microscopy. These data demonstrate the high-quality of the films grown by this technique. A model was created to fit to the data for VO2 in its metallic and insulating phases in the near infrared spectral region. The permittivity and refractive index of the ALD VO2 agreed well with the other fabrication methods in its insulating phase, but showed a difference in its metallic state. Finally, the analysis of the films&#39; optical properties enabled the creation of a wavelength- and temperature-dependent model of the complex optical refractive index for developing VO2 as a tunable refractive index material.

Thin films (100-1000 &#197;) of vanadium dioxide (VO2) were created by atomic-layer deposition (ALD) on sapphire substrates. Following this, the optical properties were characterized through the metal-insulator transition of VO2. From the measured optical properties, a model was created to describe the tunable refractive index of VO2.

二氧化钒原子层沉积与温度依赖性光学模型

Vanadium dioxide is a material that has a reversible metal-insulator phase change near 68 &#176;C. To grow VO2 on a wide variety of substrates, with ...

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven effective in gas adsorption, separations, and catalysis. MOFs are most commonly synthesized as bulk powder, requiring additional processes to adhere them to functional devices and fabrics that risk decreasing the powder porosity and adsorption capacity. Here, we demonstrate a method of first coating fabrics with metal oxide films using atomic layer deposition (ALD). This process creates conformal films of controllable thickness on each fiber, while providing a more reactive surface for MOF nucleation. By submerging the ALD coated fabric in solution during solvothermal MOF synthesis, the MOFs create a conformal, well-adhered coating on the fibers, resulting in a MOF-functionalized fabric, without additional adhesion materials that may block MOF pores and functional sites. Here we demonstrate two solvothermal synthesis methods. First, we form a MIL-96(Al) layer on polypropylene fibers using synthetic conditions that convert the metal oxide to MOF. Using initial inorganic films of varying thicknesses, diffusion of the organic linker into the inorganic allows us to control the extent of MOF loading on the fabric. Second, we perform a solvothermal synthesis of UiO-66-NH2 in which the MOF nucleates on the conformal metal oxide coating on polyamide-6 (PA-6) fibers, thereby producing a uniform and conformal thin film of MOF on the fabric. The resulting materials can be directly incorporated into filter devices or protective clothing and eliminate the maladroit qualities of loose powder.

Solvothermal Synthesis of MIL-96 and UiO-66-NH2 on Atomic Layer Deposited Metal Oxide Coatings on Fiber Mats

Metal-organic frameworks are effective in gas storage and heterogeneous catalysis, but typical synthesis methods result in loose powders that are difficult to incorporate into smart materials. We demonstrate a method of first coating fabrics with ALD metal oxides, resulting in conformal films of MOF on the fabrics during solvothermal synthesis.

溶剂热合成 MIL-96 和 UiO-66-NH2在纤维垫上原子层沉积金属氧化物涂层上的合成

Metal-organic frameworks (MOFs), which contain reactive metal clusters and organic ligands allowing for large porosities and surface areas, have proven ...

用定向能沉积法生产 Ti-6Al-4V 层厚度的单车道多层沉积

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