压力和温度对拓电子材料的影响X2Y3 (X = As,Sb,Bi;Y = Se,Te) 使用第一原理
Le Fang1,2, Chen Chen1,3, Xionggang Lu1,4
1State Key Laboratory of Advanced Special Steel, School of Materials Science and Engineering, ICQMS and Physics Department, Shanghai University, Shanghai 200444, China. luxg@shu.edu.cn.
Physical chemistry chemical physics : PCCP
|July 27, 2023
概括
这项研究探讨了压力和温度如何影响像Bi2Se3.3这样的拓绝缘体. 研究人员发现了Bi2Se3在拓和普通状态之间过渡的特定压力点,为材料特性提供了洞察力.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
背景情况:
- 三级石灰化物X2Y3 (X = As,Sb,Bi;Y = Se,Te) 是拓应用的有前途的材料.
- 了解它们在外部刺激下的电子和拓性质对于设备工程至关重要.
研究的目的:
- 系统地研究X2Y3化合物的热和拓性质.
- 分析压力和温度对它们的电子带结构和拓状态的影响.
- 为了识别压力诱导的电子拓过渡和取决于温度的材料行为.
主要方法:
- 用第一原则计算来研究电子性质.
- 准的近似被用来调查格子扩张与温度.
- 瓦尼尔电荷中心进化被计算为确定拓不变量.
主要成果:
- 在5GPa左右的石化物 (Bi2Se3) 中观察到电子拓过渡,压力下转向间接带间隙.
- 对于化物和化物,随着温度的增加,分析了格子膨胀和带隙变化和体积热膨胀系数的变化.
- 预计石化物 (Bi2Se3) 在 -8 GPa 时将从拓绝缘体转变为普通绝缘体.
- 二 (As2Se3) 被确定为普通绝缘体,而其他四种化合物在所有研究条件下仍然是强大的拓绝缘体.
结论:
- 压力和温度等外部刺激显著改变X2Y3材料的拓性质.
- 特定化合物表现出可调节的拓状态,使其在先进的电子设备中具有潜在的应用.
- 这些发现为设计和使用基于其相变的拓绝缘体提供了理论基础.
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