中国物理B ›› 2013, Vol. 22 ›› Issue (5): 57401-057401.doi: 10.1088/1674-1056/22/5/057401

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Quenched Fe moment in the collapsed tetragonal phase of Ca1-xPrxFe2As2

马龙a, 吉高峰a, 代佳a, Saha S Rb, Drye Tb, Paglione Jb, 于伟强a   

  1. a Department of Physics, Renmin University of China, Beijing 100872, China;
    b Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
  • 收稿日期:2013-02-27 修回日期:2013-03-12 出版日期:2013-04-01 发布日期:2013-04-01
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11074304 and 11222433), the National Basic Research Program of China (Grant Nos. 2010CB923004 and 2011CBA00112). Work at UMD supported by AFOSR-MURI (Grant No. FA9550-09-1-0603).

Quenched Fe moment in the collapsed tetragonal phase of Ca1-xPrxFe2As2

Ma Long (马龙)a, Gi Gao-Feng (吉高峰)a, Dai Jia (代佳)a, Saha S Rb, Drye Tb, Paglione Jb, Yu Wei-Qiang (于伟强)a   

  1. a Department of Physics, Renmin University of China, Beijing 100872, China;
    b Center for Nanophysics and Advanced Materials, Department of Physics, University of Maryland, College Park, MD 20742, USA
  • Received:2013-02-27 Revised:2013-03-12 Online:2013-04-01 Published:2013-04-01
  • Contact: Yu Wei-Qiang E-mail:wqyu_phy@ruc.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant Nos. 11074304 and 11222433), the National Basic Research Program of China (Grant Nos. 2010CB923004 and 2011CBA00112). Work at UMD supported by AFOSR-MURI (Grant No. FA9550-09-1-0603).

摘要: We report 75As NMR studies on single crystals of rare-earth doped iron pnictide superconductor Ca1-xPrxFe2As2. In both cases of x=0.075, 0.15, a large increase of νq upon cooling is consistent with the tetragonal-collapsed tetragonal structure transition. A sharp drop of the Knight shift is also seen just below the structural transition, which suggests the quenching of Fe local magnetism, and therefore offers important understanding of the collapsed tetragonal phase. At even low temperatures, the 1/75T1 is enhanced and forms a peak at T≈ 25 K, which may be caused by the magnetic ordering of the Pr3+ moments or spin dynamics of mobile domain walls.

关键词: quenched Fe moment, collapsed tetragonal phase, iron pnictides, nuclear magnetic resonance

Abstract: We report 75As NMR studies on single crystals of rare-earth doped iron pnictide superconductor Ca1-xPrxFe2As2. In both cases of x=0.075, 0.15, a large increase of νq upon cooling is consistent with the tetragonal-collapsed tetragonal structure transition. A sharp drop of the Knight shift is also seen just below the structural transition, which suggests the quenching of Fe local magnetism, and therefore offers important understanding of the collapsed tetragonal phase. At even low temperatures, the 1/75T1 is enhanced and forms a peak at T≈ 25 K, which may be caused by the magnetic ordering of the Pr3+ moments or spin dynamics of mobile domain walls.

Key words: quenched Fe moment, collapsed tetragonal phase, iron pnictides, nuclear magnetic resonance

中图分类号:  (Pnictides and chalcogenides)

  • 74.70.Xa
74.25.nj (Nuclear magnetic resonance) 76.60.-k (Nuclear magnetic resonance and relaxation)