Abstract
A temperature dependence of the Landau coefficients for an itinerant-electron metamagnet is discussed on the spin fluctuation model, by taking the magnetovolume effect into account. Both of the first- and second-order transitions at the Curie temperature are possible to take place for an itinerant-electron ferromagnet with a negative mode-mode coupling among spin fluctuations. It is shown that depends strongly on the pressure near the boundary between the first- and second-order transitions. On the other hand, the spontaneous magnetization at does not depend so much on the pressure. These results are consistent with the observed results for the pyrite compound the Laves phase compound and other ferromagnets which show a metamagnetic transition in the paramagnetic phase.
- Received 8 May 2001
DOI:https://doi.org/10.1103/PhysRevB.65.024413
©2001 American Physical Society