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Title: Non-Griffiths-like clustered phase above the Curie temperature of the doped perovskite cobaltite La{sub x-1}Sr{sub x}CoO{sub 3}.

Abstract

The existence of preformed clusters above the Curie temperature of the doped perovskite manganites is well established and, in many cases, conforms to the expectations for a Griffiths phase. We show here that the canonical perovskite cobaltite (La{sub 1?x}Sr{sub x}CoO{sub 3}) also exhibits a clustered state above the Curie point in the ferromagnetic phase. The formation of magnetic clusters at a well-defined temperature (T*) is revealed in the small-angle neutron scattering and dc susceptibility. Remarkably, the characteristics of this clustered state appear quite unlike those of a Griffiths phase; the deviation from Curie-Weiss behavior is opposite to expectations and is field independent, while T* does not correspond to the undiluted Curie temperature. These results demonstrate that, although the Griffiths model may apply to many systems with quenched disorder, it is not universally applicable to randomly doped transition metal oxides.

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org.:
USDOE Office of Science (SC); National Science Foundation (NSF); ACS PRF; National Institute of Standards and Technology (NIST)
OSTI Identifier:
920574
Report Number(s):
ANL/MSD/JA-60556
TRN: US0805298
DOE Contract Number:  
DE-AC02-06CH11357
Resource Type:
Journal Article
Resource Relation:
Journal Name: Phys. Rev. B; Journal Volume: 76; Journal Issue: 2007
Country of Publication:
United States
Language:
ENGLISH
Subject:
72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS; CURIE POINT; NEUTRONS; OXIDES; PEROVSKITE; SCATTERING; TRANSITION ELEMENTS

Citation Formats

He, C., Torija, M. A., Wu, J., Lynn, J. W., Zheng, H., Mitchell, J. F., Leighton, C., Materials Science Division, Univ. Minnesota, and NIST. Non-Griffiths-like clustered phase above the Curie temperature of the doped perovskite cobaltite La{sub x-1}Sr{sub x}CoO{sub 3}.. United States: N. p., 2007. Web. doi:10.1103/PhysRevB.76.014401.
He, C., Torija, M. A., Wu, J., Lynn, J. W., Zheng, H., Mitchell, J. F., Leighton, C., Materials Science Division, Univ. Minnesota, & NIST. Non-Griffiths-like clustered phase above the Curie temperature of the doped perovskite cobaltite La{sub x-1}Sr{sub x}CoO{sub 3}.. United States. doi:10.1103/PhysRevB.76.014401.
He, C., Torija, M. A., Wu, J., Lynn, J. W., Zheng, H., Mitchell, J. F., Leighton, C., Materials Science Division, Univ. Minnesota, and NIST. Mon . "Non-Griffiths-like clustered phase above the Curie temperature of the doped perovskite cobaltite La{sub x-1}Sr{sub x}CoO{sub 3}.". United States. doi:10.1103/PhysRevB.76.014401.
@article{osti_920574,
title = {Non-Griffiths-like clustered phase above the Curie temperature of the doped perovskite cobaltite La{sub x-1}Sr{sub x}CoO{sub 3}.},
author = {He, C. and Torija, M. A. and Wu, J. and Lynn, J. W. and Zheng, H. and Mitchell, J. F. and Leighton, C. and Materials Science Division and Univ. Minnesota and NIST},
abstractNote = {The existence of preformed clusters above the Curie temperature of the doped perovskite manganites is well established and, in many cases, conforms to the expectations for a Griffiths phase. We show here that the canonical perovskite cobaltite (La{sub 1?x}Sr{sub x}CoO{sub 3}) also exhibits a clustered state above the Curie point in the ferromagnetic phase. The formation of magnetic clusters at a well-defined temperature (T*) is revealed in the small-angle neutron scattering and dc susceptibility. Remarkably, the characteristics of this clustered state appear quite unlike those of a Griffiths phase; the deviation from Curie-Weiss behavior is opposite to expectations and is field independent, while T* does not correspond to the undiluted Curie temperature. These results demonstrate that, although the Griffiths model may apply to many systems with quenched disorder, it is not universally applicable to randomly doped transition metal oxides.},
doi = {10.1103/PhysRevB.76.014401},
journal = {Phys. Rev. B},
number = 2007,
volume = 76,
place = {United States},
year = {Mon Jan 01 00:00:00 EST 2007},
month = {Mon Jan 01 00:00:00 EST 2007}
}