...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Role of defects in the metal-insulator transition in VO_2 and V_2O_3
【24h】

Role of defects in the metal-insulator transition in VO_2 and V_2O_3

机译：VO_2和V_2O_3在金属绝缘体转换中的缺陷在缺陷中的作用

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

The vanadates VO2 and V2O3 are prototypical examples of strongly correlated materials that exhibit a metalinsulator transition. While the phase transitions in these materials have been studied extensively, there is a limited understanding of how the properties of these materials are affected by the presence of defects and doping. In this study we investigate the impact of native point defects in the form of Frenkel defects on the structural, magnetic, and electronic properties of VO2 and V2O3, using first-principles calculations. In VO2 the vanadium Frenkel pairs lead to a nontrivial insulating state. The unpaired vanadium interstitial bonds to a single dimer, which leads to a trimer that has one singlet state and one localized single-electron S = 1/2 state. The unpaired broken dimer created by the vanadium vacancy also has a localized S = 1/2 state. Thus, the insulating state is created by the singlet dimers, the trimer, and the two localized S = 1/2 states. Oxygen Frenkel pairs, on the other hand, lead to a metallic state in VO2, but are expected to be present in much lower concentrations. In contrast, the Frenkel defects in V2O3 do not directly suppress the insulating character of the material. However, the disorder created by defects in V2O3 alters the local magnetic moments and in turn reduces the energy cost of a transition between the insulating and conducting phases of the material. We also find self-trapped small polarons in V2O3, which has implications for transport properties in the insulating phase.
机译：钒醛vO2和V2O3是表现出晶体化器过渡的强相关材料的原型示例。虽然这些材料中的相转变已经广泛研究，但有限地了解这些材料的性质如何受到缺陷和掺杂的存在影响。在这项研究中，我们使用第一原理计算来调查弗雷克尔缺陷的形式对弗雷克尔缺陷的形式对VO2和V2O3的电子性质的影响。在VO2中，钒Frenkel对导致非活动绝缘状态。未配对的钒间质键到单个二聚体，这导致具有一个单向状态和一个局部单电子S = 1/2状态的三聚体。由钒空缺产生的未配对破碎二聚体也具有局部的S = 1/2状态。因此，绝缘状态由单向二聚体，三聚体和两个局部的S = 1/2状态产生。另一方面，氧气Frenkel对导致VO2中的金属状态，但预计将以低得多的浓度存在。相比之下，V2O3中的弗雷塞尔缺陷不直接抑制材料的绝缘特性。然而，V2O3中缺陷产生的疾病改变了局部磁性矩，又降低了材料的绝缘和导电相之间的过渡的能量成本。我们还在V2O3中找到了自捕获的小精子，这对绝缘阶段的运输性质具有影响。

著录项

  • 来源
    《Physical review》 |2019年第21期|214103.1-214103.9|共9页
  • 作者

    Wickramaratne Darshana; Bernstein Noam; Mazin I. I.;

  • 作者单位

    US Naval Res Lab Ctr Computat Mat Sci Washington DC 20375 USA;

    US Naval Res Lab Ctr Computat Mat Sci Washington DC 20375 USA;

    US Naval Res Lab Ctr Computat Mat Sci Washington DC 20375 USA;

  • 收录信息
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号