ANALYSIS AND INTERPRETATION OF TIME-DEPENDENT MAGNETIC PHENOMENA (INVITED)

Authors
Citation
L. Folks et R. Street, ANALYSIS AND INTERPRETATION OF TIME-DEPENDENT MAGNETIC PHENOMENA (INVITED), Journal of applied physics, 76(10), 1994, pp. 6391-6395
Citations number
23
Categorie Soggetti
Physics, Applied
Journal title
ISSN journal
00218979
Volume
76
Issue
10
Year of publication
1994
Part
2
Pages
6391 - 6395
Database
ISI
SICI code
0021-8979(1994)76:10<6391:AAIOTM>2.0.ZU;2-E
Abstract
Time dependence of intensity of magnetization is the result of thermal activation of metastable domain processes. The simple (M,H) represent ation of magnetic behavior may be extended to include time dependent e ffects using a constitutive equation. Magnetic processes may be descri bed by the movement of a point over a three-dimensional surface with c oordinates M, H, and M. The parameters required to define the surface, Lambda (or fluctuation field H-f) and chi, may be derived from measur ements of the time dependence of magnetization. A review of the utiliz ation of the constitutive equation is given and simple methods for obt aining the material parameters from conventional magnetic viscosity me asurements (under constant applied field conditions) are described. Me asurements of Lambda in particular provide additional quantitative inf ormation on magnetization processes which may be compared with predict ions of proposed models of magnetization. The results of measurements of Lambda and susceptibility chi for CrO2 powders and sintered and mel t-quenched rare earth-transition metal borides are presented. Conclusi ons about the magnetization mechanisms of these materials are discusse d.