Exchange interactions in heavy rare-earths RCo2 compounds

Abstract

The magnetic behaviour of RCo2 (R = Tm, Er, Ho, Tb) compounds, above the Curie temperatures, Tc, has been analysed. The interdependent exchange interactions at the level of unit cell are discussed in correlation with R5d band polarizations. The clusters evidenced by SANS experiments in paramagnetic region, having correlation length of ≅ 7 Å, were associated with the exchange coupled atoms at the level of the unit cell. The exchange interactions are not so high to induce a magnetic ordered phase.