Potts models and the critical behavior of a cubic ferromagnet with fourth- and sixth-order anisotropy
Abstract
The critical behavior of the magnetization of a cubic ferromagnet in a magnetic field is analyzed for all field directions when both fourth- and sixth-order anisotropy are present. Results are presented for K1>0 and all κ (K2K1). For -6<κ<9 the phase diagram is of the three-state Potts type. For κ>9 a 60° rotation of the three-state Potts diagram is obtained at high fields and a reentrant feature at lower fields. For κ=9, a special critical point appears on the [111] axis. The connection between this result and an extended version of the Landau theory is made. Finally, the κ<=-6 ([110] hard) diagram is displayed and the nature of the critical points, lines, and surfaces discussed.
- Publication:
-
Physical Review B
- Pub Date:
- July 1984
- DOI:
- 10.1103/PhysRevB.30.181
- Bibcode:
- 1984PhRvB..30..181C