The dynamics of spontaneous hydrogen segregation in LaFe13-xSixHy

被引：20

作者：

Baumfeld, Oliver L. ^{[1
]}

Gercsi, Zsolt ^{[1
,2
,3
]}

Krautz, Maria ^{[4
,5
]}

Gutfleisch, Oliver ^{[6
]}

Sandeman, Karl G. ^{[1
]}

机构：

[1] Univ London Imperial Coll Sci Technol & Med, Dept Phys, Blackett Lab, London SW7 2AZ, England

[2] Univ Dublin Trinity Coll, CRANN, Dublin 2, Ireland

[3] Univ Dublin Trinity Coll, Sch Phys, Dublin 2, Ireland

[4] Leibniz Inst Solid State & Mat Res Dresden, D-01069 Dresden, Germany

[5] Tech Univ Dresden, Inst Mat Sci, D-01069 Dresden, Germany

[6] Tech Univ Darmstadt, D-64287 Darmstadt, Germany

来源：

JOURNAL OF APPLIED PHYSICS | 2014年 / 115卷 / 20期

基金：

英国工程与自然科学研究理事会;

关键词：

MAGNETIC ENTROPY CHANGE; ELECTRON METAMAGNETIC TRANSITION; MAGNETOSTRICTION; COMPOUND; LA(FE; MN;

D O I：

10.1063/1.4879099

中图分类号：

O59 [应用物理学];

学科分类号：

摘要：

By means of time-and temperature-dependent magnetization measurements, we demonstrate that the timescale of hydrogen diffusion in partially hydrogenated LaFe13-xSixHy is of the order of hours, when the material is held at temperatures close to its as-prepared Curie temperature, T-C0. The diffusion constant is estimated to be D approximate to 10(-15)-10(-16) m(2) s(-1) at room temperature. We examine the evolution of a magnetically phase-separated state upon annealing for 3 days at a range of temperatures around T-C0 and show that the thermodynamic driving force behind hydrogen diffusion and phase segregation may be attributed to the lower free energy of hydrogen interstitials in the ferromagnetic state relative to the paramagnetic state. (C) 2014 AIP Publishing LLC.

引用

页数：4

共 27 条

[1] Stability and Magnetocaloric Properties of Sintered La(Fe, Mn, Si)13Hz Alloys [J].