Property and cation valence engineering in entropy-stabilized oxide thin films
Property and cation valence engineering in entropy-stabilized oxide thin films
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DOI：
10.1103/physrevmaterials.4.100401
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发表时间：
2020-10-19
影响因子：
3.4
通讯作者：
Maria, Jon-Paul
中科院分区：
文献类型：
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作者：
Kotsonis, George N.;Meisenheimer, Peter B.;Maria, Jon-Paul
我们提供了典型熵稳定氧化物（ESO） mg0.2 ni0.2 co0.2 cu0.2 zn0.2的外延薄膜的数据，揭示了薄膜生长过程中晶格参数和性能随衬底温度的变化呈系统趋势，微观结构变化可以忽略不计。在低于350℃的衬底温度下生长的薄膜中，较大的净Co价导致更小的晶格参数，更小的光学带隙和更强的磁交换偏置。对这一现象的观察表明，在ESO合成过程中，热力学和动力学之间存在复杂的相互作用；特别是热历史，氧化学势和熵。除了ESO系统的组成自由度之外，恒定金属元素比例下原子结构的细微差别也会对性能产生强烈影响，同时使物理表征复杂化，并为性能调整和开发提供了机会。
We present data for epitaxial thin films of the prototypical entropy-stabilized oxide (ESO), Mg0.2Ni0.2Co0.2Cu0.2Zn0.2O, that reveals a systematic trend in lattice parameter and properties as a function of substrate temperature during film growth with negligible changes in microstructure. A larger net Co valence in films grown at substrate temperatures below 350 degrees C results in a smaller lattice parameter, a smaller optical band gap, and stronger magnetic exchange bias. Observation of this phenomena suggests a complex interplay between thermodynamics and kinetics during ESO synthesis; specifically thermal history, oxygen chemical potential, and entropy. In addition to the compositional degrees of freedom available to ESO systems, subtle nuances in atomic structure at constant metallic element proportions can strongly influence properties, simultaneously complicating physical characterization and providing opportunities for property tuning and development.