SPIN REORIENTATION PHENOMENA IN RFE10V2 INTERMETALLIC COMPOUNDS (R=DY AND ND)

A high Curie point and a high uniaxial anisotropy near room temperature are the most interesting features of the new iron rich R Fe12-xMx alloys (R=rare earth, MTi, V, Cr...) in order to be used as starting materials for permanent magnets. When R is a rare earth ion with planar anisotropy spin reorientation transition (SRT) phenomena will take place due to the variation with temperature and competition of the anisotropy of the R and Fe magnetic sublattices. We have studied the SRT phenomena in RFe10V2 (RDy and Nd) using two different experimental techniques. A.C. initial magnetic susceptibility measurements have allowed us to determine the SRT temperature associated with the critical fluctuation of the SRT angle, being TSR=140 K and TSR=112 K for DyFe10V2 and Nd2Fe10V2 respectively. On the other side we have measured the angular dependence of the parallel and perpendicular component of the magnetization to the applied magnetic field, which has permitted to obtain the SRT angle. From the aforementioned experiments we have obtained that at low temperatures a cone magnetic structure is stabilized in both compounds and from that we can conclude the relevance of the high order term in the crystal electric field interaction. © 1990.