The effect of the annealing temperature on the structural and magnetic properties of the manganites compounds

被引：50

作者：

Othmani, S. ^{[1
]}

Bejar, M. ^{[1
]}

Dhahri, E. ^{[1
]}

Hlil, E. K. ^{[2
]}

机构：

[1] Fac Sci Sfax, Appl Phys Lab, Sfax 3000, Tunisia

[2] Inst Neel, CNRS, Lab Cristallog, Dept MCMF, F-38042 Grenoble 9, France

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2009年 / 475卷 / 1-2期

关键词：

Electron-doped manganites; Sol-gel method; Crystal structure and grain size; Annealing effect; Structural and magnetic transition; SYSTEM;

D O I：

10.1016/j.jallcom.2008.08.005

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

The electron-doped manganites La1-xCexMnO3 (x = 0.3, 0.4 and 0.5) compounds were prepared by the sol-gel method and annealed at two different temperatures of 1400 degrees C and 900 degrees C. The morphology, crystallographic and magnetic properties of these compounds were studied as function of annealing temperature. The morphology study shows a decrease of the grain size for the temperature of 900 degrees C. The grain size is found to affect the structure which is confirmed by the Rietveld refinements of X-ray diffraction revealing a transition from the orthorhombic phase to the rhombohedral one when decreasing the annealing temperature from 1400 degrees C to 900 degrees C. This transition is accompanied by an enhancement of the one-electron bandwidth inducing an increase of the magnetization and the Curie temperature. The magnetocaloric study indicates the existence of a transition from second to first order when decreasing annealing temperature from 1400 degrees C to 900 degrees C. (C) 2008 Elsevier B.V. All rights reserved.

引用

页码：46 / 50

页数：5

共 14 条

[1] The effect of a cation radii on physical properties of doped manganites [J].