STUDY OF THE IRON CONTRIBUTION TO THE 3D-SUBLATTICE ANISOTROPY IN SOME UNIAXIAL YCOFE STRUCTURES DERIVED FROM THE CACU5 UNIT-CELL

The effects of the Fe substitution for Co on the anisotropy of uniaxia l structures (YCo3, Y2Co7, Y5Co19, YCo5) all derived from the parent C aCu5 unit cell were studied. The unique Singular Point Detection (SPD) technique was used to measure temperature and composition dependence of the anisotropy. A characteristic behaviour of both Co and Fe anisot ropies was individuated. The overall Fe sublattice anisotropy is alway s opposite and 2-3 times larger than that of Co. From the temperature behaviour of the anisotropy constant (K1), spin reorientation transiti ons (SRT) were predicted at temperature values which depend on Fe cont ent. ac susceptibility measurements seem to confirm the presence of SR T. The magnetic phase diagrams of mixed Y-Co-Fe compounds were derived .