第一个原则研究在 (111) -Strained BiFeO3中石空隙形成的研究
Lu Xia1, Thomas Tybell2, Sverre M Selbach1
1Department of Material Science and Engineering, NTNU Norwegian University of Science and Technology, N-7491 Trondheim, Norway.
Materials (Basel, Switzerland)
|November 27, 2024
概括
长轴应变显著改变BiFeO3薄膜中的Bi空缺. 压缩应变稳定了Bi空位和Bi-O对,影响了膜静电量和导电域壁.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 计算材料科学科学 计算材料科学
背景情况:
- 轴应变严重影响氧化物薄膜特性.
- 张力薄膜中的点缺陷度仍未得到充分研究.
- 薄膜固体测量的实验测量具有挑战性,需要计算方法.
研究的目的:
- 在BiFeO3 (BFO) 中研究 (111) 表皮轴应变对Bi空位和Bi-O空位对的影响.
- 在不同的应变条件下确定这些点缺陷的形成和稳定性.
- 将应变诱导的缺陷变化与薄膜静态度和域壁形成相关联.
主要方法:
- 使用密度函数理论 (DFT) 的第一原则计算.
- 模拟BFO薄膜受到控制的压力 (-4%) 和拉力 (4%) (111) 表轴应变.
- 计算Bi空位和Bi-O空位对 (在平面内和平面外) 的形成度.
主要成果:
- 压缩应变使Bi空位形成度减少0.88 eV;拉伸应变使其增加0.39 eV.
- 不平面的Bi-O空位对在压力 (1.49 eV减小) 和拉力 (1.05 eV减小) 应变下表现出增强的稳定性.
- 平面内空隙对由压力应变稳定,但不受拉力应变的影响.
结论:
- 轴菌株在控制BFO薄膜生长过程中的生物静态度方面发挥着至关重要的作用.
- 应变介导缺陷形成影响了BFO中导电域壁的出现.
- 计算DFT提供了对应力氧化物薄膜中缺陷行为的重要见解.
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