兴奋剂对多价值状态,电子结构和不同大气层下LaCrO3光波段间隙的影响:一个综合的实验和密度功能理论研究
Edward M Sabolsky1, Javier A Mena1, Víctor Mendoza-Estrada2,3,4
1Department of Mechanical, Materials, and Aerospace Engineering, West Virginia University, Morgantown, West Virginia 26506, United States.
ACS applied electronic materials
|March 31, 2025
概括
用Ca,Sr和Mn合兰酸盐 (LaCrO3) 改变了其电子结构和光带间隙. 这项研究证明了Cr氧化状态的过渡,这对于调整LaCrO3矿中电性质至关重要.
科学领域:
- 材料科学 材料科学 材料科学
- 固态化学 固态化学
- 矿氧化物 矿氧化物
背景情况:
- 兰酸盐 (LaCrO3) 是一种矿氧化物,在高温设备中具有潜在的应用.
- 了解兴奋剂对其电子和光学性能的影响对于材料优化至关重要.
研究的目的:
- 研究Ca,Sr和Mn兴奋剂对LaCrO3.3的价值状态,电子结构和光带间隙的影响.
- 为了将这些变化与电导率和氧化状态过渡相关联.
主要方法:
- 通过使用修改的Pechini sol-gel方法合成合的LaCrO3 (La1-xCaxCrO3,La1-xSrxCrO3,La0.8Sr0.2Cr1-xMnxO3).
- 通过反应性烧结进行凝结,以达到>96%的理论密度.
- 在不同的大气和温度下使用X射线光电子谱学 (XPS) 进行表征.
- 使用反射UV对光谱光度测量的光学带间隙测量.
- 通过密度函数理论 (DFT) 计算进行验证.
主要成果:
- 使用Ca,Sr和Mn的兴奋剂导致电子结构的修改和光带间隙 (2.81-3.12 eV) 的减少,随着兴奋剂度的增加.
- XPS分析揭示了缺陷状态和因替代而导致的阴离价值补偿.
- 首次证明了在减少大气中的Sr2+/Mn3+联合合样本中的Cr4+到Cr3+氧化/还原过渡.
- DFT计算支持实验发现,在较高的兴奋剂水平下,频段间隙减少.
结论:
- 在Cr氧化状态中观察到的转变归因于二价/三价的存在.
- 兴奋剂提供了一条调整LaCrO3矿电性质的途径.
- 研究结果为开发用于各种低温和高温应用的基于LaCrO3的材料提供了洞察力.
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