EFFECT OF THE VANADIUM CONTENT ON THE RARE-EARTH ANISOTROPY BEHAVIOR IN DYFE12-XVX COMPOUNDS

The spin reorientation transitions (SRTs) were investigated in DyFe12- xVx (x=1.5, 2.0, 2.75, 4.0) compounds by a.c. susceptibility vs. tempe rature measurements. The SRT temperature is shifted towards lower valu es with increasing vanadium content from T-SR=170 K for x=1.5 to T-SR= 125 K for x=2.75. The crystal field parameter A(2)(0) was calculated t aking into account the preference 8(i) crystal site and considering th e nearest neighbourhood of the rare earth ion. Charges of surrounding Fe and V atoms were established by applying the chemical bond model pr oposed by Pauling. The absolute value of the A(2)(0) parameter decreas es when the content of vanadium increases in the 8(i) position which e xplains the T-SR shift.