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Title: Magnetic properties of TM{endash}Co{endash}Fe{endash}Ti spinel oxides (abstract)

Abstract

Spin glass-like behavior has been recently observed in a ceramic Zn{sub 0.5}Co{sub 0.9}Fe{sub 1.2}Ti{sub 0.4}O{sub 4} spinel oxide. This motivated our interest to study how the spin glass-like behavior of magnetic clusters in a diamagnetic matrix correlates to that of nonmagnetic or weakly magnetic clusters in a ferromagnetic matrix, Moessbauer effect, ac susceptibility, field cooled and zero field cooled magnetization, hysteresis loops, and {gamma}{endash}{gamma} perturbed angular correlation (PAC) have been measured for TM{sub 0.5{minus}x}Co{sub 0.9}Fe{sub 1.2+x}Ti{sub 0.4}O{sub 4} (x=0.0 and 0.2) spinel oxide with TM=Zn and Cu. The variation of coercive field with temperature has been found to fit a double exponential function form H{sub c}(T)=H{sub 1}e{sup {minus}{beta}1T}+H{sub 2}e{sup {minus}{beta}2T} where H{sub i} and {beta}{sub i} are constants for the sample with x=0.0 and TM=Zn. The exponential increase in coercive field can be linked to increased effective clusters arising from ions occupying A and B sites with Fe on both sites. This is in agreement with the Moessbauer measurements which show superparamagnetic fluctuations. The ac susceptibility and Moessbauer spectra for Zn{sub 0.5}Co{sub 0.9}Fe{sub 1.2}Ti{sub 0.4}O{sub 4} show a glass transition temperature (about 320 K). Room temperature PAC measurements on Hf doped samples with TM=Zn showed different interaction frequencies, consistent withmore » magnetic order in the Fe enriched case. Different behavior is observed in the sample with Cu for which the ordering temperature is about 480 K. {copyright} {ital 1997 American Institute of Physics.}« less

Authors:
; ; ; ; ;  [1];  [2]
  1. Centro Brasileiro de Pesquisas Fisicas, Rio de Janeiro (Brazil)
  2. Department of Physics, University of Natal, Durban (South Africa)
Publication Date:
OSTI Identifier:
544312
Report Number(s):
CONF-961141-
Journal ID: JAPIAU; ISSN 0021-8979; TRN: 9709M0358
Resource Type:
Journal Article
Journal Name:
Journal of Applied Physics
Additional Journal Information:
Journal Volume: 81; Journal Issue: 8; Conference: 41. annual conference on magnetism and magnetic materials, Atlanta, GA (United States), 12-15 Nov 1996; Other Information: PBD: Apr 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; CERAMICS; MAGNETIC PROPERTIES; SPINELS; PERTURBED ANGULAR CORRELATION; COERCIVE FORCE; SUPERPARAMAGNETISM; ZINC COMPOUNDS; COPPER COMPOUNDS; COBALT COMPOUNDS; ZINC OXIDES; COBALT OXIDES; IRON OXIDES; TITANIUM OXIDES; MAGNETIC SUSCEPTIBILITY; MOESSBAUER EFFECT; MAGNETIZATION; PHASE TRANSFORMATIONS

Citation Formats

Giordanengo, B, de Melo, M A, Takeuchi, A Y, Silva, P R, Saitovitch, H, Baggio-Saitovitch, E, and Moyo, T. Magnetic properties of TM{endash}Co{endash}Fe{endash}Ti spinel oxides (abstract). United States: N. p., 1997. Web. doi:10.1063/1.364710.
Giordanengo, B, de Melo, M A, Takeuchi, A Y, Silva, P R, Saitovitch, H, Baggio-Saitovitch, E, & Moyo, T. Magnetic properties of TM{endash}Co{endash}Fe{endash}Ti spinel oxides (abstract). United States. doi:10.1063/1.364710.
Giordanengo, B, de Melo, M A, Takeuchi, A Y, Silva, P R, Saitovitch, H, Baggio-Saitovitch, E, and Moyo, T. Tue . "Magnetic properties of TM{endash}Co{endash}Fe{endash}Ti spinel oxides (abstract)". United States. doi:10.1063/1.364710.
@article{osti_544312,
title = {Magnetic properties of TM{endash}Co{endash}Fe{endash}Ti spinel oxides (abstract)},
author = {Giordanengo, B and de Melo, M A and Takeuchi, A Y and Silva, P R and Saitovitch, H and Baggio-Saitovitch, E and Moyo, T},
abstractNote = {Spin glass-like behavior has been recently observed in a ceramic Zn{sub 0.5}Co{sub 0.9}Fe{sub 1.2}Ti{sub 0.4}O{sub 4} spinel oxide. This motivated our interest to study how the spin glass-like behavior of magnetic clusters in a diamagnetic matrix correlates to that of nonmagnetic or weakly magnetic clusters in a ferromagnetic matrix, Moessbauer effect, ac susceptibility, field cooled and zero field cooled magnetization, hysteresis loops, and {gamma}{endash}{gamma} perturbed angular correlation (PAC) have been measured for TM{sub 0.5{minus}x}Co{sub 0.9}Fe{sub 1.2+x}Ti{sub 0.4}O{sub 4} (x=0.0 and 0.2) spinel oxide with TM=Zn and Cu. The variation of coercive field with temperature has been found to fit a double exponential function form H{sub c}(T)=H{sub 1}e{sup {minus}{beta}1T}+H{sub 2}e{sup {minus}{beta}2T} where H{sub i} and {beta}{sub i} are constants for the sample with x=0.0 and TM=Zn. The exponential increase in coercive field can be linked to increased effective clusters arising from ions occupying A and B sites with Fe on both sites. This is in agreement with the Moessbauer measurements which show superparamagnetic fluctuations. The ac susceptibility and Moessbauer spectra for Zn{sub 0.5}Co{sub 0.9}Fe{sub 1.2}Ti{sub 0.4}O{sub 4} show a glass transition temperature (about 320 K). Room temperature PAC measurements on Hf doped samples with TM=Zn showed different interaction frequencies, consistent with magnetic order in the Fe enriched case. Different behavior is observed in the sample with Cu for which the ordering temperature is about 480 K. {copyright} {ital 1997 American Institute of Physics.}},
doi = {10.1063/1.364710},
journal = {Journal of Applied Physics},
number = 8,
volume = 81,
place = {United States},
year = {1997},
month = {4}
}