Open AccessTHE MEAN FIELD THEORY FOR SPONTANEOUS MAGNETIZATION OF A NON-UNIFORM FERROMAGNET
Author(s) -
FuCho Pu,
Dingsheng Wang
Publication year - 1978
Publication title -
wuli xuebao
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.199
H-Index - 47
ISSN - 1000-3290
DOI - 10.7498/aps.27.439
Subject(s) - magnetization , condensed matter physics , eigenfunction , curie temperature , ferromagnetism , spontaneous magnetization , physics , eigenvalues and eigenvectors , field (mathematics) , mean field theory , curie–weiss law , magnetic field , quantum mechanics , mathematics , pure mathematics
Starting from the nonlinear differential equation for a non-uniform ferromagnet in mean field approximation, we apply the bifurcation theory to discuss the pheno-mena of magnetic phase transition. It is shown that (1) the Curie point of the system is determined by the maximium eigenvalue of linearized equation; (2) the space varia-tion of magnetization just below the Curie point is described by the corresponding eigenfunction; (3) the temperature dependence of magnetization is represented by the parameter a(T)(l-T:Tc)1/2. In the later parts of our paper, the application of this method is illustrated by examples of thin films and a simple model proposed for describ-ing non-uniform ferromagnet.