ANISOTROPY IN THE PARAMAGNETIC PHASE OF RENI(5) HEXAGONAL INTERMETALLIC COMPOUNDS (RE=TB,HO,ND)

A new alternative experimental method, the measurement of the polar de pendence of the parallel and perpendicular magnetization components, i s reported in order to determine all the individual components of the magnetic susceptibility tensors of second and fourth rank. Suitable th eoretical expressions have been obtained for hexagonal systems with 6/ mmm, 622, 6mm, and (6)over bar m2> point symmetries. An extensive expe rimental study, following the method proposed, has been performed in t he paramagnetic phase of RENi(5) (RE = Tb, Ho, Nd) hexagonal intermeta llic compounds. The interpretation of these results in terms of a micr oscopic model involving crystalline-electric-field, bilinear exchange, and total quadrupolar interactions is also reported.