...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Magnetocrystalline interactions in MnCr_2O_4 spinel
【24h】

Magnetocrystalline interactions in MnCr_2O_4 spinel

机译：MnCr_2O_4尖晶石中的磁晶相互作用

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

In this work we present a magnetic, structural, and electron spin resonance (ESR) study of the geometrically frustrated MnCr_2O_4 spinel in an extended range of T (2-1000 K). At the lowest temperature (T<18 K) the ESR lineshape is compatible with the coexistence of spiral and ferrimagnetic spin ordering. Above T_C (≈41 K), magnetic susceptibility (x) and ESR intensity coincide with each other showing the typical behavior of a ferrimagnet. From the x(T) vs T dependence, absolute values for the three exchange constants J_(MnCr), J_(CrCr), and J_(MnMn) were determined. Our results indicate that (ⅰ) these values are approximately independent of T, (ⅱ) the antiferromagnetic direct Cr-Cr exchange is the main interaction, and (ⅲi) J_(MnMn) is indeed not negligible as compared with J_(MnCr) and J_(CrCr). One noticeable anomaly in the temperature dependence of the ESR linewidth is observed at T ≈ 450 K. This behavior is accounted by a 30% variation in the extrapolated high-temperature linewidth and it is attributed to a crystalline distortion not reported previously. Experiments of high-temperature x-ray diffraction allowed us to associate this distortion to a deformation of the oxygen sublattice. ESR and x-ray results are both compatible with a more symmetric high-temperature structure.
机译：在这项工作中，我们提出了在扩展的T（2-1000 K）范围内对几何受挫的MnCr_2O_4尖晶石进行的磁，结构和电子自旋共振（ESR）研究。在最低温度（T <18 K）下，ESR线形与螺旋和亚铁磁自旋有序并存。在T_C（≈41K）以上，磁化率（x）和ESR强度彼此一致，显示出铁磁体的典型行为。从x（T）对T的依赖关系，确定三个交换常数J_（MnCr），J_（CrCr）和J_（MnMn）的绝对值。我们的结果表明（ⅰ）这些值与T几乎无关，（ⅱ）反铁磁直接Cr-Cr交换是主要相互作用，并且（ⅲi）与J_（MnCr）和J_（CrCr）。在T≈450 K处观察到一个与ESR线宽的温度相关的明显异常。这种现象是由推断的高温线宽变化了30％引起的，并且归因于先前未报道的结晶变形。高温X射线衍射实验使我们能够将这种畸变与氧亚晶格的变形联系起来。 ESR和X射线结果均与更对称的高温结构兼容。

著录项

  • 来源
    《Physical review》 |2009年第10期|104418.1-104418.8|共8页
  • 作者

    E. Winkler; S. Blanco Canosa; F. Rivadulla; M. A. Lopez-Quintela; J. Rivas; A. Caneiro; M. T. Causa; M. Tovar;

  • 作者单位

    Centro Atomico Bariloche, S. C. de Bariloche, 8400 Rio Negro, Argentina;

    Departamentos de Quimica-Fisica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain;

    Departamentos de Quimica-Fisica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain;

    Departamentos de Quimica-Fisica, Universidad de Santiago de Compostela, 15782 Santiago de Compostela, Spain;

    Departamentos Fisica Aplicada, Universidad de Santiago de Compostela , 15782 Santiago de Compostela, Spain;

    Centro Atomico Bariloche, S. C. de Bariloche, 8400 Rio Negro, Argentina;

    Centro Atomico Bariloche, S. C. de Bariloche, 8400 Rio Negro, Argentina;

    Centro Atomico Bariloche, S. C. de Bariloche, 8400 Rio Negro, Argentina;

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

    exchange and superexchange interactions; electron paramagnetic resonance and relaxation;

    机译：交换和超级交换互动;电子顺磁共振和弛豫;

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