在Eu-doped BaTiO3中高压铁电类半金属状态
Mrinmay Sahu1, Bishnupada Ghosh1, Boby Joseph2
1National Centre for High Pressure Studies, Department of Physical Sciences, Indian Institute of Science Education and Research Kolkata, Mohanpur Campus, Mohanpur, 741246 Nadia, West Bengal, India.
The Journal of chemical physics
|September 4, 2024
概括
高压将Eu-doped酸 (BaTiO3) 从铁电转化为半金属. 局部结构变化持续存在,在极端条件下实现独特的铁电类半金属状态.
科学领域:
- 材料科学 材料科学 材料科学
- 凝聚物质物理学 凝聚物质物理学
- 固态化学 固态化学
背景情况:
- 乙酸 (BaTiO3) 是一种众所周知的铁电材料,在电容器和传感器中具有应用.
- 将BaTiO3与欧 (Eu) 等稀土元素进行合,可以改变其电气和结构性质.
- 在极端条件下,如高压下,了解合BaTiO3的行为对于探索新的电子状态至关重要.
研究的目的:
- 研究Eu-doped BaTiO3.3的高压 (HP) 结构,振动和介电性质.
- 确定压力诱导的相变及其对材料铁电和电子行为的影响.
- 在HP条件下阐明铁电和半金属状态的共存.
主要方法:
- 角度解析的X射线衍射 (XRD) 用于结构分析.
- 拉曼光谱检测振动模式和相位过渡.
- 介电电容度测量以评估压力下的电性质.
主要成果:
- 在1.4 GPa以上,观察到由压力诱导的结构相从四角形到混合立方和四角形相的过渡.
- 拉曼模式表明从铁电四边形转向电立方相的过渡,但局部结构不均性仍然存在.
- 发现了压力诱导的载体移位的证据,表明半金属状态,以及局部化的铁电排序集群.
结论:
- 高压诱导了Eu-doped BaTiO3 的相变,导致结构相的共存.
- 尽管过渡,当地的结构不均性保持自发的两极分化,有助于一个铁电类似的状态.
- 这项研究揭示了在高压和极端量子极限下,欧化BaTiO3中具有一种新的铁电类半金属状态.
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