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Title: Griffiths phase, spin-phonon coupling, and exchange bias effect in double perovskite Pr{sub 2}CoMnO{sub 6}

The ceramic Pr{sub 2}CoMnO{sub 6} of double perovskite structure is prepared by a solid-state reaction and the magnetic properties, phonon behaviors are studied in detail. Two ferromagnetic transitions at T{sub C1} ∼ 172 K and T{sub C2} ∼ 140 K are observed in the temperature-dependent magnetization curves, respectively. Furthermore, a detail analysis on the magnetic susceptibility reveals that a short-range ferromagnetic clustered state exists above T{sub C1}, which can be well described as the Griffiths phase with a well-defined Griffiths temperature T{sub G} ∼ 210 K. The presence of the B-site antisite defects is considered to contribute to the observed Griffiths singularity. Temperature-dependent Raman scattering experiment reveals an obvious softening of the phonon mode involving stretching vibrations of the (Co/Mn)O{sub 6} octahedra in FM temperature regions, indicating a close correlation between magnetism and lattice in Pr{sub 2}CoMnO{sub 6}. On the other hand, it is found that the phonon softening extends up to T{sub G}, which further confirms the preformation of the short-range ferromagnetic clusters up to T{sub G}. Moreover, the field-cooling magnetic hysteresis loop reveals that exchange bias phenomena is present, which is supposed to origin from the exchange coupling between Co/Mn ordered ferromagnetic phases with antiferromagnetic antiphase boundaries caused by the partially Co/Mn antisite disorders. These findings givemore » a systematic understanding on the magnetic interaction in Pr{sub 2}CoMnO{sub 6} which is closely related to the lattice and atomic distribution, and add special interest for application of this material.« less
Authors:
; ; ; ; ;  [1]
  1. Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China)
Publication Date:
OSTI Identifier:
22402669
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 116; Journal Issue: 19; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; ANTIFERROMAGNETISM; CERAMICS; COOLING; CORRELATIONS; COUPLING; DIAGRAMS; HYSTERESIS; MAGNETIC SUSCEPTIBILITY; MAGNETIZATION; ORIGIN; PEROVSKITE; PHONONS; RAMAN EFFECT; SINGULARITY; SOLIDS; SPIN; TEMPERATURE DEPENDENCE