Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite

The colossal magnetoresistive of Lao.67Cao.33Mnl-x V x03 (LCMVO), to x=O.30, ceramics have been studied. X-ray diffraction (XRD) patterns show single-phase perovskite structure with the presence of some minor impurities for all the samples. The systems exhibit tetragonal and orthorhombic distorte...

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Main Author:	Koh, Song Foo
Format:	Thesis
Language:	English English
Published:	2001
Subjects:	Magnetoresistance Perovskite - Structure-activity relationships
Online Access:	http://psasir.upm.edu.my/id/eprint/9244/1/FSAS_2001_20.pdf
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id	my-upm-ir.9244
record_format	uketd_dc
spelling	my-upm-ir.92442024-02-13T03:25:19Z Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite 2001-04 Koh, Song Foo The colossal magnetoresistive of Lao.67Cao.33Mnl-x V x03 (LCMVO), to x=O.30, ceramics have been studied. X-ray diffraction (XRD) patterns show single-phase perovskite structure with the presence of some minor impurities for all the samples. The systems exhibit tetragonal and orthorhombic distorted perovskite structures, which resulted from the Jahn Teller distortion. Paramagnetic - Ferromagnetic phase transitions were observed in the X'-temperature curves for all the samples. The Curie temperature, Tc shifts to lower temperature as vanadium, dysprosium and zirconium doping increases respectively, which indicate the loss of ferromagnetic order. Zirconium doping is observed to decrease the Te more than the effect of other dopants. For LCMVO system, samples with x=0.0l, 0.02, 0.03 and 0.30 show an enhancement of volume susceptibility as the temperature increases from 110 K- 140 K, 120 K- 142 K, 123 K-140 K and 77 K-94 K respectively. These enhancements are due to the formation of magnetic clusters m the samples. For LCMDO system, all the samples show the typical ferromagnetic-paramagnetic transition and no spin glass behaviour was detected. However, in LCMZO system, the samples with x>0.05 show ferromagnetic onset followed by a cusp when cooling from room temperature. The anomalies were due to the formation of spin glass in the sample. The transport properties show the transition of semiconducting to metallic conductivity at T p. The existence of T p and T c was found correlated. Magnetoresistance Perovskite - Structure-activity relationships 2001-04 Thesis http://psasir.upm.edu.my/id/eprint/9244/ http://psasir.upm.edu.my/id/eprint/9244/1/FSAS_2001_20.pdf text en public masters Universiti Putra Malaysia Magnetoresistance Perovskite - Structure-activity relationships Faculty of Science and Environmental Studies English
institution	Universiti Putra Malaysia
collection	PSAS Institutional Repository
language	English English
topic	Magnetoresistance Perovskite - Structure-activity relationships
spellingShingle	Magnetoresistance Perovskite - Structure-activity relationships Koh, Song Foo Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
description	The colossal magnetoresistive of Lao.67Cao.33Mnl-x V x03 (LCMVO), to x=O.30, ceramics have been studied. X-ray diffraction (XRD) patterns show single-phase perovskite structure with the presence of some minor impurities for all the samples. The systems exhibit tetragonal and orthorhombic distorted perovskite structures, which resulted from the Jahn Teller distortion. Paramagnetic - Ferromagnetic phase transitions were observed in the X'-temperature curves for all the samples. The Curie temperature, Tc shifts to lower temperature as vanadium, dysprosium and zirconium doping increases respectively, which indicate the loss of ferromagnetic order. Zirconium doping is observed to decrease the Te more than the effect of other dopants. For LCMVO system, samples with x=0.0l, 0.02, 0.03 and 0.30 show an enhancement of volume susceptibility as the temperature increases from 110 K- 140 K, 120 K- 142 K, 123 K-140 K and 77 K-94 K respectively. These enhancements are due to the formation of magnetic clusters m the samples. For LCMDO system, all the samples show the typical ferromagnetic-paramagnetic transition and no spin glass behaviour was detected. However, in LCMZO system, the samples with x>0.05 show ferromagnetic onset followed by a cusp when cooling from room temperature. The anomalies were due to the formation of spin glass in the sample. The transport properties show the transition of semiconducting to metallic conductivity at T p. The existence of T p and T c was found correlated.
format	Thesis
qualification_level	Master's degree
author	Koh, Song Foo
author_facet	Koh, Song Foo
author_sort	Koh, Song Foo
title	Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
title_short	Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
title_full	Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
title_fullStr	Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
title_full_unstemmed	Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite
title_sort	colossal magnetoresistance of la0.67ca0.33mn1-xax)3 [a=v, dy and zr] perovskite
granting_institution	Universiti Putra Malaysia
granting_department	Faculty of Science and Environmental Studies
publishDate	2001
url	http://psasir.upm.edu.my/id/eprint/9244/1/FSAS_2001_20.pdf
_version_	1794018808600461312

Colossal magnetoresistance of La0.67Ca0.33Mn1-xAx)3 [A=V, Dy and Zr] perovskite

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