Effect of disorder on the magnetic properties of LaMn0.5Fe0.5O3

TitleEffect of disorder on the magnetic properties of LaMn0.5Fe0.5O3
Publication TypeJournal Article
Year of Publication2005
AuthorsBhame, SD, Joly, VLJoseph, Joy, PAlias
JournalPhysical Review B
Volume72
Issue5
Pagination054426
Date PublishedAUG
Type of ArticleArticle
ISSN1098-0121
Abstract

Polycrystalline LaMn0.5Fe0.5O3 is synthesized by a low-temperature method and the magnetic properties of the resulting powder have been studied after annealing the sample in air at different temperatures in the range 200 degrees C-1350 degrees C. Room temperature Mossbauer spectroscopic studies show that the Fe ions are present in the +3 oxidation state in the material. However, the magnetic properties vary widely in an unexpected manner when samples are annealed at different temperatures. Zero field cooled magnetization studies show a cusp below 100 K, for the sample annealed at 200 degrees C, indicating a spin-glass-like or superparamagnetic behavior. However, this cusp disappears completely when the sample is annealed at 700 degrees C but still showing a magnetic hysteresis loop with reduced magnetization at low temperatures. The cusp again appears when the sample is annealed at higher temperatures with increasing low-temperature magnetization. EPR and IR spectroscopic studies indicate changes in the distribution of Mn3+ and Fe3+ ions in the lattice. The overall results can be explained in terms of random distribution of Mn3+ and Fe3+ ions in the lattice and formation of some magnetic clusters, with the degree of distribution of the ions varying for samples annealed at different temperatures.

DOI10.1103/PhysRevB.72.054426
Type of Journal (Indian or Foreign)

Foreign

Impact Factor (IF)3.718
Divison category: 
Physical and Materials Chemistry