...
首页> 外文期刊>Physical review >Ferromagnetism versus slow paramagnetic relaxation in Fe-doped Li_3N
【24h】

Ferromagnetism versus slow paramagnetic relaxation in Fe-doped Li_3N

机译:铁掺杂的Li_3N中的铁磁与慢顺磁弛豫

获取原文
获取原文并翻译 | 示例
           

摘要

We report on isothermal magnetization, Mossbauer spectroscopy, and magnetostriction as well as temperature-dependent alternating-current (ac) susceptibility, specific heat, and thermal expansion of single crystalline and polycrystalline Li_2(Li_(1-x)Fe_x)N with x = 0 and x≈0.30. Magnetic hysteresis emerges at temperatures below T ≈ 50 K with coercivity fields of up to μ_0H = 11.6 T at T = 2K and magnetic anisotropy energies of 310 K (27 meV). The ac susceptibility is strongly frequency-dependent (f= 10-10000 Hz) and reveals an effective energy barrier for spin reversal of ∆E ≈ 1100 K (90 meV). The relaxation times follow Arrhenius behavior for T > 25 K. For T < 10 K, however, the relaxation times of τ ≈ 10~(10) s are only weakly temperature-dependent, indicating the relevance of a quantum tunneling process instead of thermal excitations. The magnetic entropy amounts to more than 25 J mol_(Fe)~(-1) K~(-1) which significantly exceeds R ln2, the value expected for the entropy of a ground-state doublet. Thermal expansion and magnetostriction indicate a weak magnetoelastic coupling in accordance with slow relaxation of the magnetization. The classification of Li_2(Li_(1-x)Fe_x)N as ferromagnet is stressed and contrasted with highly anisotropic and slowly relaxing paramagnetic behavior.
机译:我们报告了单晶和多晶Li_2(Li_(1-x)Fe_x)N的x = 0和x≈0.30。磁滞现象出现在T≈50 K以下的温度下,矫顽力场在T = 2K时高达μ_0H= 11.6 T,磁各向异性能为310 K(27 meV)。交流磁化率与频率密切相关(f = 10-10000 Hz),并揭示了自旋反转∆E≈1100 K(90 meV)的有效能垒。对于T> 25 K,弛豫时间遵循Arrhenius行为。但是,对于T <10 K,τ≈10〜(10)s的弛豫时间仅与温度密切相关,表明量子隧穿过程的相关性与热无关激发。磁熵超过25 J mol_(Fe)〜(-1)K〜(-1),大大超过R ln2,这是基态双峰态的熵的期望值。根据磁化的缓慢松弛,热膨胀和磁致伸缩指示弱的磁弹性耦合。 Li_2(Li_(1-x)Fe_x)N作为铁磁体的分类受到强调,并与高各向异性和缓慢松弛的顺磁行为形成对比。

著录项

  • 来源
    《Physical review》 |2018年第6期|064419.1-064419.11|共11页
  • 作者单位

    EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany;

    EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany,The Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA;

    Chair of Solid State Chemistry, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany;

    Institute for Solid State and Materials Physics, TU Dresden, D-01069 Dresden, Germany;

    Institute for Solid State and Materials Physics, TU Dresden, D-01069 Dresden, Germany;

    EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany,Department of Physics, IIT Tirupati, Tirupati 517506, India;

    EP VI, Center for Electronic Correlations and Magnetism, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany;

    Chair of Solid State Chemistry, Institute of Physics, University of Augsburg, D-86159 Augsburg, Germany;

    The Ames Laboratory, Iowa State University, Ames, Iowa 50011, USA,Department of Physics and Astronomy, Iowa State University, Ames, Iowa 50011, 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