Influence of oxygen on the giant magnetocaloric effect of Gd5Si1.95Ge2.05

被引：20

作者：

Wu, W

Tsokol, AO

Gschneidner, KA

Sampaio, JA

机构：

[1] Iowa State Univ Sci & Technol, Ames Lab, Mat & Engn Phys Program, Ames, IA 50011 USA

[2] Xihua Univ, Dept Mat Sci & Engn, Chengdu 610039, Sichuan, Peoples R China

[3] Iowa State Univ Sci & Technol, Dept Mat Sci & Engn, Ames, IA 50011 USA

来源：

JOURNAL OF ALLOYS AND COMPOUNDS | 2005年 / 403卷 / 1-2期

关键词：

Gd5Si1.95Ge2.05; influence of oxygen; giant magnetocaloric effect; magnetocaloric effect; magnetic transformation; magnetization; X-ray diffraction;

D O I：

10.1016/j.jallcom.2005.06.001

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 influence of oxygen on the 5:4 (i.e. 5Gd:4[Si+Ge]) monoclinic Gd5Si1.95Ge2.05 was investigated. Five oxygen-containing alloys, Gd5Si1.95Ge2.05Ox, were prepared with x varying from 0.05 to 0.5. The addition of small amounts of oxygen, x <= 0.10, stabilizes the orthorhombic form at high temperature, such that both phases are present in the arc-melted alloys. At higher oxygen contents, x >= 0. 15, oxygen tends to favor the decomposition of the Gd5Si1.95Ge2.05 phase into the GdSiyGe1-y, (1:1) and the Gd5SizGe3-z (5:3) phases. The solubility of oxygen in the two polymorphic 5:4 phases is less than x = 0.05. The presence of oxygen in the monoclinic form destroys the giant magnetocaloric effect, apparently by preventing the monoclinic phase from transforming to the orthorhombic modification at the Curie temperature giving rise to a second order magnetic transformation, (c) 2005 Elsevier B.V. All rights reserved.

引用

页码：118 / 123

页数：6

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