...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Physical review >Elastic and magnetic effects on the infrared phonon spectra of MnF_2
【24h】

Elastic and magnetic effects on the infrared phonon spectra of MnF_2

机译：MnF_2红外声子光谱的弹性和磁效应

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

We measured the temperature-dependent infrared reflectivity spectra of MnF_2 between 4 and 600 K. We show that the phonon spectrum undergoes a clear renormalization at T_N. The ab initio calculation we performed on this compound accurately predicts the magnitude and the direction of the changes in the phonon parameters across the antiferromagnetic transition, showing that they are mainly induced by the magnetic order. In this material, we found that the dielectric constant is mostly from phonon origin. The large change in the lattice parameters with temperature seen by x-ray diffraction as well as the A_(2u) phonon softening below T_N indicate that magnetic order induced distortions in MnF_2 are compatible with the ferroelectric instabilities observed in TiO_2, FeF_2 and other rutile-type fluorides. This study also shows the anomalous temperature evolution of the lower energy E_u mode in the paramagnetic phase, which can be compared to that of the B_(1g) phonon vseen by Raman spectroscopy in many isostructural materials. This was interpreted as being a precursor of a phase transition from rutile to CaCl_2 structure which was observed under pressure in ZnF_2.
机译：我们测量了MnF_2在4至600 K之间随温度变化的红外反射光谱。我们表明，声子光谱在T_N处经历了明显的重新归一化。我们对该化合物进行的从头算计算准确地预测了反铁磁跃迁中声子参数变化的幅度和方向，表明它们主要是由磁序引起的。在这种材料中，我们发现介电常数主要来自声子。 X射线衍射观察到的晶格参数随温度的大变化以及T_N以下的A_（2u）声子软化表明MnF_2中的磁序感应畸变与TiO_2，FeF_2和其他金红石型中观察到的铁电不稳定性兼容类型的氟化物。这项研究还显示了顺磁相中较低能级E_u模式的温度异常演化，可以通过拉曼光谱将其与B_（1g）声子vseen在许多同结构材料中的温度演化进行比较。这被解释为是在压力下在ZnF_2中观察到的从金红石结构转变为CaCl_2结构的相变的前体。

著录项

  • 来源
    《Physical review》 |2010年第5期|P.054412.1-054412.10|共10页
  • 作者

    R. Schleck; rnY. Nahas; rnR. P. S. M. Lobo; rnJ. Varignon; rnM. B. Lepetit; C. S. Nelson; R. L. Moreira;

  • 作者单位

    Laboratoire de Physique et Etude des Materiaux (LPEM), ESPCI, CNRS UPR5, Universite Pierre et Marie Curie, 10 rue Vauquelin,F-75231 Paris Cedex 5, France;

    rnLaboratoire de Physique et Etude des Materiaux (LPEM), ESPCI, CNRS UPR5, Universite Pierre et Marie Curie, 10 rue Vauquelin,F-75231 Paris Cedex 5, France;

    rnLaboratoire de Physique et Etude des Materiaux (LPEM), ESPCI, CNRS UPR5, Universite Pierre et Marie Curie, 10 rue Vauquelin,F-75231 Paris Cedex 5, France;

    rnCRISMAT, ENSICAEN, CNRS UMR 6508, 6 bd. Marechal Juin, 14050 Caen, France;

    rnCRISMAT, ENSICAEN, CNRS UMR 6508, 6 bd. Marechal Juin, 14050 Caen, France;

    rnNational Synchrotron Light Source, Brookhaven National Laboratory, Upton, New York 11973, USA;

    rnDepartamento de Fisica, ICEx, Universidade Federal de Minas Gerais, CP 702, Belo Horizonte 31123-970, MG, Brazil;

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

    infrared and raman spectra;

    机译：红外光谱和拉曼光谱;

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