Sm-Co-Ti三元系相关系及某些单相化合物的结构与磁性

Sm-Co-Ti PHASE DIAGRAM AND STRUCTURAL AND MAGNETIC PROPERTIES OF SOME SINGLE-PHASE COMPOUNDS

通过X射线衍射和磁性测量研究了Sm Co Ti三元体系富Co区固相线下的相关系 ,并探索了Co基 3:2 9型化合物存在的可能性 ,进而研究了某些单相化合物的结构和磁性 .实验表明 ,该体系中存在三个三元化合物SmCo7-xTix,Sm2 Co17-xTix 和SmCo12 -xTix,其固溶区分别为 0 .32≤x≤ 0 .5 4,0≤x≤ 1.13和 1.45≤x≤ 1.95 .按Sm9.3 1Co90 -xTix(3≤x≤ 15 )成分配料 ,Sm按其质量的 15 % ,2 0 % ,2 5 %三个比例过量加入 ,在 130 3— 140 3K温度范围内退火 ,均未发现 3∶2 9相 .在制备出的SmCo12 -xTix,和Sm2 Co17-xTix 两个系列化合物中 ,随着Ti含量的增加 ,它们的居里温度和饱和磁化强度都单调降低 .Sm2 Co17-xTix 化合物在居里温度以下表现为单轴各向异性 ,而SmCo12 -xTix 化合物表现为面各向异性 .SmCo12 -xTix 和Sm2 Co17-xTix 化合物 1.5K下的磁晶各向异性场随Ti含量的变化都呈现一个极大值 。

The phase diagram of Go-rich Sm-Go-Ti system was obtained by X-ray diffraction analysis and magnetic measurement. It was found that there exist three series of compounds, SmCo7-xTix, Sm2Co17-xTix and SmCo12-xTix. The formation ranges for these three series are 0.32 less than or equal tox less than or 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 phase 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% added, at temperatures ranging from 1303 to 1403 K. It was also found that the Curie temperatures T-C and saturation magnetization M-s decrease with increasing Ti content for both SmCo12-xTix and Sm2Co17-xTix compounds. Below T-C, the uniaxial and planar anisotropies were observed for Sm2Co17-xTix and SmCo12-xTix compounds, respectively. The anisotropy fields B-a measured at 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 associated with the preferential substitution of Ti for Co.