Accessing a growth window for SrVO3 thin films
Accessing a growth window for SrVO3 thin films
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DOI：
10.1063/1.4932198
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发表时间：
2015-10-05
影响因子：
4
通讯作者：
Engel-Herbert, Roman
中科院分区：
文献类型：
--
作者：
Brahlek, Matthew;Zhang, Lei;Engel-Herbert, Roman
采用杂化分子束外延技术，在（001）（La0.3Sr0.7）（Al0.65Ta0.35）O-3衬底上生长出具有一定阳离子通量的SrVO3薄膜，其中热浸电池产生Sr通量，V由金属-有机前驱体氧化三异丙醇钒（VTIP）提供。在保持Sr通量不变的情况下，系统地改变VTIP通量，发现在一定范围内SrVO3薄膜的结构和电子性能保持不变。在生长窗口内，薄膜的本征晶格参数和剩余电阻率最小，表明薄膜的缺陷浓度最低，当阳离子通量比偏离理想生长条件时，薄膜的缺陷浓度迅速增加。反射高能电子衍射表明，在此范围内生长的薄膜表面光滑，衍射图中没有额外的斑点，而在此范围内生长的薄膜表面粗糙，含有额外的晶相。结果表明，在足够高的生长温度下，存在一个SrVO3生长窗口，在该窗口中，高质量的化学计量膜可以以稳健、高可重复性的方式生长，并且不受无意的通量变化的影响。(C) 2015 AIP出版有限责任公司
Stoichiometric SrVO3 thin films were grown over a range of cation fluxes on (001) (La0.3Sr0.7)(Al0.65Ta0.35)O-3 substrates using hybrid molecular beam epitaxy, where a thermal effusion cell was employed to generate a Sr flux and V was supplied using the metal-organic precursor vanadium oxytriisopropoxide (VTIP). By systematically varying the VTIP flux while keeping the Sr flux constant, a range of flux ratios were discovered in which the structural and electronic properties of the SrVO3 films remained unaltered. The intrinsic film lattice parameter and residual resistivity were found to be the smallest inside the growth window, indicating the lowest defect concentration of the films, and rapidly increased for cation flux ratios deviating from ideal growth condition. Reflection high-energy electron diffraction showed that films grown within this range had smooth surfaces and diffraction patterns were free of additional spots, while otherwise the growing surface was rough and contained additional crystalline phases. Results show the existence of a SrVO3 growth window at sufficiently high growth temperature, in which high-quality, stoichiometric films can be grown in a robust, highly reproducible manner that is invulnerable to unintentional flux variation. (C) 2015 AIP Publishing LLC.