Sm-Co-Ti phase diagram and structural and magnetic properties of some single-phase compounds

The phase diagram of Go-rich Sm-Go-Ti system was obtained by X-ray diffract ion analysis and magnetic measurement. It was found that there exist three series of compounds, SmCo7-xTix, Sm2Co17-xTix and SmCo12-xTix. The formatio n ranges for these three series are 0.32 less than or equal tox less than o r equal to0.54, 0 less than or equal tox less than or equal to1.13 and 1.45 less than or equal tox less than or equal to1.95, respectively. The 3:29 p hase was not found after annealing Sm9.31Co90-xTix(3 less than or equal tox less than or equal to 15) prepared with an excess Sm of 15%, 20% and 25% a dded, at temperatures ranging from 1303 to 1403 K. It was also found that t he Curie temperatures T-C and saturation magnetization M-s decrease with in creasing Ti content for both SmCo12-xTix and Sm2Co17-xTix compounds. Below T-C, the uniaxial and planar anisotropies were observed for Sm2Co17-xTix an d SmCo12-xTix compounds, respectively. The anisotropy fields B-a measured a t 1.5 K for both SmCo12-xTix and Sm2Co17-xTix compounds as a function of Ti content exhibits a peak at certain compositions, which is thought to be as sociated with the preferential substitution of Ti for Co.