期刊
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
卷 446, 期 -, 页码 68-79出版社
ELSEVIER
DOI: 10.1016/j.jmmm.2017.09.001
关键词
Manganites; X-ray diffraction; Magnetocaloric effect; Critical field analysis; Universal master curve
资金
- SERB-Department of Science and Technology, India [EMR/2014/000761]
In this study, we have investigated magnetic behavior, magnetocaloric effect and critical exponent analysis of La0.7-xEuxSr0.3MnO3 (x = 0.0, 0.1, 0.2, 0.3) manganites synthesized through solid state reaction route. The crystallographic data obtained from refinement of X-ray diffraction patterns reveal that crystal structure changes from rhombohedral (for x = 0.0) to orthorhombic (for x > 0.1). The average ionic radius of A-site is decreased from 1.384 angstrom (for x = 0.0) to 1.360 angstrom (for x = 0.3) with Eu3+ substitution which in turn decreases the Mn-O-Mn bond angles. Magnetization measurements are performed in the vicinity of TC to determine magnetocaloric effect (MCE) and critical field behavior. The maximum magnetic entropy change (Delta S-M(max)) (for mu(0)Delta H = 6T) increases with the Eu3+ substitution from 3.88 J/kg K (for x = 0.0) to 5.03 J/kg K (for x = 0.3) at the transition temperature. The critical field behaviour of compounds was analysed using various methods such as modified Arrott plots, Kouvel-Fisher method and critical isotherm to determine critical temperature and critical exponents (beta, gamma and delta). The obtained critical exponents are in good accordance with scaling relation. The temperature dependence of the order parameter n, for different magnetic fields, is studied using the relation Delta S-M alpha H-n. The values of n are found to obey the Curie-Weiss law for temperatures above the transition temperature. The rescaled change in entropy data for all compounds collapses into the same universal curve, revealing a second order phase transition. (C) 2017 Elsevier B.V. All rights reserved.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据