HIGH-TEMPERATURE HYSTERESIS AND THERMOREMANENCE OF SINGLE-DOMAIN MAGHEMITE

被引：82

作者：

OZDEMIR, O

机构：

[1] Department of Physics, Erindale College, University of Toronto, Mississauga

来源：

PHYSICS OF THE EARTH AND PLANETARY INTERIORS | 1990年 / 65卷 / 1-2期

关键词：

D O I：

10.1016/0031-9201(90)90081-8

中图分类号：

P3 [地球物理学]; P59 [地球化学];

学科分类号：

0708 ; 070902 ;

摘要：

Magnetic properties have been measured for acicular maghemite crystals of single-domain (SD) size between room temperature and the Curie temperature T(C) of 645-degrees-C. The transformation of maghemite to hematite takes place at 752-degrees-C, far above T(C) of the present gamma-Fe2O3. The observed high-temperature stability of this material made it possible to study the thermoremanent magnetization (TRM) and high-temperature hysteresis properties of gamma-Fe2O3. The temperature dependence of coercive force shows that the main contribution to the coercivity is from shape anisotropy. Magnetization reversal is dominated by incoherent rotation. The experimental results are consistent with the fanning mode of reversal in a chain of spheres. The weak-field TRM was linear with applied field, as predicted from Neel SD theory.

引用

页码：125 / 136

页数：12

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