Abstract
We have calculated some properties of a ferromagnet using a Heisenberg Hamiltonian with a biquadratic exchange term added. The constant-coupling approximation was employed. If the strength of the biquadratic exchange relative to the bilinear is given by a dimensionless parameter α, there is a critical value αc at which the phase transition changes character from second order for αα>αc. The spontaneous magnetization, the exchange energy, and the spin-correlation function show discontinuous jumps at α=αc and unstable behavior for α>αc. © 1975 The American Physical Society.
Recommended Citation
H. A. Brown, "Biquadratic Exchange And First-order Ferromagnetic Phase Transitions," Physical Review B, vol. 11, no. 11, pp. 4725 - 4727, American Physical Society, Jan 1975.
The definitive version is available at https://doi.org/10.1103/PhysRevB.11.4725
Department(s)
Physics
International Standard Serial Number (ISSN)
0163-1829
Document Type
Article - Journal
Document Version
Final Version
File Type
text
Language(s)
English
Rights
© 2023 American Physical Society, All rights reserved.
Publication Date
01 Jan 1975
