SPIN-REORIENTATION TRANSITIONS AND MAGNETIC-ANISOTROPY IN TBFE11-XCOXTI COMPOUNDS

The aim of this work is to study the influence of substitution of Co f or Fe on the magnetocrystalline anisotropy and spin reorientation tran sition in TbFe11-xCoxTi (x=0;0.5;1;2;3;4;5) compounds. The anisotropy study has been performed by means of torque and magnetization measurem ents on single crystal samples. It was shown that increase of the Co c ontent in Tb(FeCo)(11)Ti compounds leads to an increase of the Curie t emperatures T-c. The temperature of the magnetic phase transition duri ng which the easy magnetic direction (EMD) changes from the c-axis via a cone to the basal plane has been found to decrease with increasing Co concentration. On the basis of the experimental results a T-x magne tic phase diagram was constructed. The appearance of phase transitions can be explained by the temperature-dependent competition between the planar Tb sublattice anisotropy and the transition metal (FeCo),, sub lattice anistropy. (C) 1998 Published by Elsevier Science S.A. All rig hts reserved.