在拉德尔斯登 - 波珀层状矿中竞争的极地和反极地结构Li2SrNb2O7
Ritesh Uppuluri1, Hirofumi Akamatsu2, Arnab Sen Gupta3
1Departments of Chemistry, Biochemistry and Molecular Biology, and Physics, The Pennsylvania State University, University Park, Pennsylvania 16802, United States.
Chemistry of materials : a publication of the American Chemical Society
|June 25, 2024
概括
研究人员在Li2SrNb2O7层叠的矿中发现了一个新的反极相. 这种由八面体层旋转驱动的过渡,为设计用于储能应用的抗铁电材料提供了见解.
科学领域:
- 材料科学 材料科学 材料科学
- 固态物理 固态物理
- 晶体学 晶体学是指结晶学.
背景情况:
- 在n=2的Ruddlesden-Popper矿中,混合不适当的铁电是由合的氧八面体旋转和极性扭曲引起的.
- 这种现象扩大了铁电和压电分层氧化物的组成景观.
研究的目的:
- 报告一个新的极 n=2 拉德尔斯登 - 波珀分层酸盐,Li2SrNb2O7.
- 为了研究其在低温下结构转化为反极相.
- 在材料设计中探索极相和反极相之间的竞争.
主要方法:
- 预测竞争阶段的第一原则计算.
- 同步射线X射线衍射和粉末中子衍射用于结构分析.
- 电气和非线性光学表征以确认相位过渡.
主要成果:
- Li2SrNb2O7呈现出一个结构转换到90 K的反极相.
- 计算预测,反极的Pnam阶段与极的A21am阶段进行能量竞争.
- 反极和极相都在能量上比中心对称的阿曼相更受青.
结论:
- 该研究确定Li2SrNb2O7作为一种新材料,呈现向反极相过渡的情况.
- 极地和反极地相之间的竞争为设计新型抗铁电材料提供了洞察力.
- 这些发现对于开发用于储能的先进静电电容器具有重要意义.
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