Keller David A, Ginsburg Adam, Barad Hannah-Noa, Shimanovich Klimentiy, Bouhadana Yaniv, Rosh-Hodesh Eli, Takeuchi Ichiro, Aviv Hagit, Tischler Yaakov R, Anderson Assaf Y, Zaban Arie
§Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742, United States.
ACS Comb Sci. 2015 Apr 13;17(4):209-16. doi: 10.1021/co500094h. Epub 2015 Mar 23.
Pulsed laser deposition (PLD) is widely used in combinatorial material science, as it enables rapid fabrication of different composite materials. Nevertheless, this method was usually limited to small substrates, since PLD deposition on large substrate areas results in severe lateral inhomogeneity. A few technical solutions for this problem have been suggested, including the use of different designs of masks, which were meant to prevent inhomogeneity in the thickness, density, and oxidation state of a layer, while only the composition is allowed to be changed. In this study, a possible way to take advantage of the large scale deposition inhomogeneity is demonstrated, choosing an iron oxide PLD-deposited library with continuous compositional spread (CCS) as a model system. An Fe₂O₃-Nb₂O₅ library was fabricated using PLD, without any mask between the targets and the substrate. The library was measured using high-throughput scanners for electrical, structural, and optical properties. A decrease in electrical resistivity that is several orders of magnitude lower than pure α-Fe₂O₃ was achieved at ∼20% Nb-O (measured at 47 and 267 °C) but only at points that are distanced from the center of the PLD plasma plume. Using hierarchical clustering analysis, we show that the PLD inhomogeneity can be used as an additional degree of freedom, helping, in this case, to achieve iron oxide with much lower resistivity.
脉冲激光沉积（PLD）在组合材料科学中被广泛应用，因为它能够快速制备不同的复合材料。然而，这种方法通常限于小尺寸衬底，因为在大面积衬底上进行PLD沉积会导致严重的横向不均匀性。针对这个问题已经提出了一些技术解决方案，包括使用不同设计的掩膜，其目的是防止层的厚度、密度和氧化态出现不均匀性，同时只允许成分发生变化。在本研究中，展示了一种利用大规模沉积不均匀性的可能方法，选择具有连续成分分布（CCS）的氧化铁PLD沉积库作为模型系统。使用PLD制备了一个Fe₂O₃-Nb₂O₅库，在靶材和衬底之间没有使用任何掩膜。使用高通量扫描仪对该库的电学、结构和光学性质进行了测量。在约20%的Nb-O（在47和267℃下测量）时，实现了电阻率的降低，其降低幅度比纯α-Fe₂O₃低几个数量级，但仅在远离PLD等离子体羽流中心的点处。通过层次聚类分析，我们表明PLD不均匀性可以用作一个额外的自由度，在这种情况下，有助于获得电阻率低得多的氧化铁。
