MAGNETIC PROPERTIES OF THE TWO SUBLATTICES MODEL OF Fe_2P IN THE LANDAU-GINZBURG APPROXIMATION

摘要

The Landau-Ginzburg approximation, considered as a way to introduce spin fluctuations in the magneticrncontribution to the free energy of magnetic materials is revisited in the special case of Fe_2P presenting two coupled magnetic sublattices. An analytic expansion of the magnetic part of the free energy can be formally derived. This lead to a self consistent equation of the moments fluctuations for the two magnetic components. The comparison with the single component case is outlined.