Oblique Antiferromagnetism. I. A Phenomenological Approach

Autor: Masukazu Igarashi, Kazukiyo Nagata
Rok vydání: 1992
Předmět:
Zdroj: Journal of the Physical Society of Japan. 61:2070-2080
ISSN: 1347-4073
0031-9015
DOI: 10.1143/jpsj.61.2070
Popis: A simple but useful phenomenological approach to the magnetism of a randomly mixed antiferromagnet B 1- x C x , in which a weak axial anisotropy of B-ions and a strong axial anisotropy of C-ions compete each other below a terminal concentration x s (≪1), is proposed. This approach is based on a two-sublattice model including angular variation of the sublattice magnetizations. The angular variation is induced by the local disarray of spin alignment and gives rise to the fourth-order anisotropy terms in the free energy. From this model, the concentration vs. external magnetic field ( x - H ) phase diagram for the random mixture is derived, which consists of four phases, namely, the paramagnetic phase, the antiferromagnetic phase, the field induced intermediate (or oblique antiferromagnetic:OAF) phase, and the spin flop phase. The magnetic resonance frequencies and the magnetization process are also derived.
Databáze: OpenAIRE