Exchange Interactions and Transition Metal Moments in Rare-Earth Compounds

Resumo

Band structure calculations have been performed on heavy rare-earths R₂Fe₁₇ compounds. The iron moments are strongly dependent on the site location and little influenced by the rare-earth partner. The Curie temperatures follow a linear trend as function of R5d band polarizations. The magneto-volume effects are well described in models where the iron moments have a rather great degree of localization. The magnetic properties of GdFe₂, at high pressures, were theoretically analysed. Both magnetic and structure transitions have been suggested, as the pressure increases.