Electrochemical material synthesis in ultra-high vacuum: elementary steps of electrochemical deposition of tantalum and niobium in ionic liquids

超高真空电化学材料合成：离子液体中钽和铌电化学沉积的基本步骤

• 批准号: 460461495
• 负责人: Professor Dr. Frank Endres
• 金额: --
• 依托单位: Institut für Elektrochemie
• 依托单位国家: 德国
• 项目类别: Research Grants
• 资助国家: 德国
• 项目状态: 未结题
• 来源: https://gepris.dfg.de/gepris/projekt/460461495?language=en
• 关键词: Electrochemical; material; synthesis; ultra; vacuum

Refractory metals such as tantalum and niobium are used in a variety of technical applications.For example, tantalum electrolytic capacitors are particularly important for today'smicroelectronics. The physico-chemical properties of tantalum allows miniaturised capacitors with high capacitance to be produced. Due to the lower occurrence of tantalum, niobium is increasingly used as a replacement material for capacitors. In addition, tantalum is widely used in medicine for implants due to its biocompatibility. Electrochemically, refractory metals cannot be deposited from aqueous and organic solutions due to their relatively negative standard electrode potentials. Hitherto, only high-temperature molten salts have proven to be efficient baths for the electrochemical deposition of several μm thick refractory metals. However, these electrolytes suffer from many technical and economic problems, such as the loss of current efficiency of the electrolysis process due to the partial dissolution of the metal after its deposition. Furthermore, corrosion problems occur at the necessary high temperatures. Due to their wide electrochemical windows (up to 6 V), ionic liquids (ILs) offer themselves aselectrolytes for the electrodeposition of these metals at low temperatures as an alternative. Ithas been shown that Ta can be electrodeposited in thin layers from TaF 5 in a range of air and water stable ionic liquids. The electrodeposition of Ta and of Nb is quite complex and not understood in detail. In addition, the high reactivity of the metals makes it difficult to analyse the deposited layers with ex-situ methods. This project now takes advantage of the fact that ionic liquids generally have a very low vapour pressure and can therefore be investigated with vacuum-based methods such as X-ray photoelectron spectroscopy (XPS) in ultra-high vacuum (UHV). We want to investigate the electrochemical processes during refractory metal deposition in ILs step by step directly in UHV with monochromatic XPS in-situ using tantalum and niobium precursors. A specially designed spectroscopy unit is available for this type of material synthesis. Starting with the analysis of the UHV electrochemistry of the pure ILs, we will then specifically investigate the influence of the precusors on the deposition. This will alsoprovide us with information about the stability of ILs and solutions due to the influence ofelectrochemistry in a very controlled atmosphere. With this approach, we will fundamentally clarify how tantalum and niobium are deposited electrochemically. In the medium-term we would like to show to electrochemical surface engineering ways to deposit refractory metals under mild conditions.

耐火金属（例如诱变金属和niobium）用于各种技术应用中。触觉的物理化学特性允许产生高电容的微型电容器。由于触觉的出现较低，尼伯族越来越多地用作电容器的替代材料。此外，由于塔塔勒姆（Tantalum）由于其生物相容性而被广泛用于医学。从电化学上，由于其相对负标准电势，无法从水性和有机溶液中沉积难治性金属。迄今为止，只有高温熔融盐才被证明是有效的浴室，用于几种厚的耐磨金属的电化学沉积。但是，这些电解质遭受了许多技术和经济问题的困扰，例如由于金属沉积后部分溶解了电解过程的当前效率。此外，在必要的高温下发生腐蚀问题。由于其宽的电化学窗户（最多6 V），离子液体（ILS）为这些金属在低温下的电沉积提供了肌源水解，作为替代方案。 ITHA被证明，可以在一系列空气和水稳定的离子液体中将TA从TAF 5的薄层中进行电沉积。 TA和NB的电沉积非常复杂，详细理解。此外，金属的高反应性使得很难使用前静态方法分析沉积的层。现在，该项目利用了一个事实，即离子液体通常具有非常低的真空压力，因此可以使用基于真空的方法（例如超高真空（UHV）中的X射线光电光谱（XP））进行研究。我们想研究使用tantalum和niobium precursor的单色XPS在UHV中直接在UHV中逐步研究ILS中的ELS中沉积过程中的电化学过程。专门设计的光谱单元可用于此类材料合成。从对纯IL的UHV电化学分析开始，我们将专门研究prefers对沉积的影响。这将使我们提供有关IL和溶液在非常受控的气氛中影响的IL和溶液稳定性的信息。通过这种方法，我们将从根本上阐明诱人和尼伯族如何通过电化学沉积。在中期，我们想展示在轻度条件下沉积难治金属的电化学表面工程方法。