MAGNETIC PHASE-TRANSITION AND MAGNETIC CRYSTALLINE ANISOTROPY IN R1-XYXFE11TI COMPOUNDS (WHERE R=PR OR TB)

Measurements of the temperature dependence of the ac susceptibility an d magnetization were used to detect the spin-reorientation transitions in R1-xY(x)Fe11Ti compounds with R = Pr or Tb. In Tb1-xY(x)Fe11Ti a s pin reorientation was detected for 0 less-than-or-equal-to x less-than -or-equal-to 0.6 and in Pr1-xY(x)Fe11Ti for 0.6 less-than-or-equal-to x less-than-or-equal-to 0.8. It is suggested that these spin reorienta tion transitions are temperature-induced magnetic phase transitions du ring which the easy magnetization direction (EMD) changes from a high- temperature c-axis via a cone to a low-temperature basal plane. At tem peratures and concentrations where the EMD of Pr1-xY(x)Fe11Ti and Tb1- xY(x)Fe11Ti is parallel to the c-axis, the magnetic anisotropy field B (A) has been determined by means of the singular point detection (SPD) technique, using a pulsed field magnetometer. A first-order magnetiza tion process (FOMP) was detected for Tb0.1Y0.9Fe11Ti below 120 K.