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Title: Mechanically-induced disorder in CaFe2As2: A 57Fe Mössbauer study

Journal Article · · Journal of Alloys and Compounds
 [1];  [2];  [2];  [2]
  1. Iowa State Univ., Ames, IA (United States); Lanzhou Univ., Gansu Province (China)
  2. Iowa State Univ., Ames, IA (United States)

57Fe Mössbauer spectroscopy was used to perform a microscopic study on the extremely pressure and strain sensitive compound, CaFe2As2, with different degrees of strain introduced by grinding and annealing. At the base temperature, in the antiferromagnetic/orthorhombic phase, compared to a sharp sextet Mössbauer spectrum of single crystal CaFe2As2, which is taken as an un-strained sample, an obviously broadened sextet and an extra doublet were observed for ground CaFe2As2 powders with different degrees of strain. The Mössbauer results suggest that the magnetic phase transition of CaFe2As2 can be inhomogeneously suppressed by the grinding induced strain to such an extent that the antiferromagnetic order in parts of the grains forming the powdered sample remain absent all the way down to 4.6 K. However, strain has almost no effect on the temperature dependent hyperfine magnetic field in the grains with magnetic order. Additional electronic and asymmetry information was obtained from the isomer shift and quadrupole splitting. Similar isomer shift values in the magnetic phase for samples with different degrees of strain, indicate that the stain does not bring any significant variation of the electronic density at 57Fe nucleus position. As a result, the absolute values of quadrupole shift in the magnetic phase decrease and approach zero with increasing degrees of strain, indicating that the strain reduces the average lattice asymmetry at Fe atom position.

Research Organization:
Ames Laboratory (AMES), Ames, IA (United States)
Sponsoring Organization:
USDOE Office of Science (SC), Basic Energy Sciences (BES)
Grant/Contract Number:
AC02-07CH11358
OSTI ID:
1239159
Alternate ID(s):
OSTI ID: 1397528
Report Number(s):
IS-J-8903; PII: S0925838815313840
Journal Information:
Journal of Alloys and Compounds, Vol. 657, Issue C; ISSN 0925-8388
Publisher:
ElsevierCopyright Statement
Country of Publication:
United States
Language:
English
Citation Metrics:
Cited by: 3 works
Citation information provided by
Web of Science

References (21)

First-order structural phase transition in CaFe 2 As 2 journal July 2008
Lattice and magnetic instabilities in CaFe 2 As 2 : A single-crystal neutron diffraction study journal September 2008
Pressure Induced Superconductivity in CaFe 2 As 2 journal July 2008
Absence of superconductivity in single-phase CaFe 2 As 2 under hydrostatic pressure journal January 2009
Pressure-induced volume-collapsed tetragonal phase of CaFe 2 As 2 as seen via neutron scattering journal November 2008
Effect of pressure on transport and magnetotransport properties in CaFe 2 As 2 single crystals journal July 2009
NMR Investigation of Superconductivity and Antiferromagnetism in CaFe 2 As 2 under Pressure journal June 2009
Structural, magnetic and superconducting phase transitions in CaFe2As2 under ambient and applied pressure journal May 2009
Control of magnetic, nonmagnetic, and superconducting states in annealed Ca(Fe 1 x Co x ) 2 As 2 journal June 2012
Thermal expansion of CaFe 2 As 2 : Effect of cobalt doping and postgrowth thermal treatment journal August 2013
Hydrostatic-pressure tuning of magnetic, nonmagnetic, and superconducting states in annealed Ca(Fe 1 x Co x ) 2 As 2 journal December 2012
Stabilization of an ambient-pressure collapsed tetragonal phase in CaFe 2 As 2 and tuning of the orthorhombic-antiferromagnetic transition temperature by over 70 K via control of nanoscale precipitates journal April 2011
First-order phase transitions in CaFe 2 As 2 single crystal: a local probe study journal March 2011
Magneto-structural coupling and harmonic lattice dynamics in CaFe 2 As 2 probed by Mössbauer spectroscopy journal June 2011
Anisotropic magnetic and superconducting properties of CaFe 2 x Co x As 2 ( x = 0 , 0.06 ) single crystals journal January 2009
Shape of spin density wave versus temperature in A Fe 2 As 2 ( A = Ca, Ba, Eu): A Mössbauer study journal April 2011
Growth of single crystals from metallic fluxes journal June 1992
EXPGUI , a graphical user interface for GSAS journal April 2001
The diffraction of X rays by distorted crystal aggregates - I journal May 1944
Liquid-Mix Disorder in Crystalline Solids: ScMnO3 journal November 1998
Model independent evaluation of overlapped Mossbauer spectra journal July 1974

Cited By (2)

57 Fe Mössbauer study of stoichiometric iron-based superconductor CaKFe 4 As 4 : a comparison to KFe 2 As 2 and CaFe 2 As 2 journal July 2017
Transition to collapsed tetragonal phase in CaFe 2 As 2 single crystals as seen by Fe 57 Mössbauer spectroscopy journal January 2016

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