Magnetic characteristics of some binary and ternary 2--17 compounds

The magnetic anisotropy of R2Co17 and R2Co17−xTx compounds with R=Y, Ce, Pr, Nd, Th and T=Mn, Fe has been investigated. The directions of easy magnetization were determined by x-ray studies on oriented powders. The several R2Co17 compounds, except for Ce2Co17, have an easy basal plane; the behavior of Ce2Co17 could not be clarified. Replacement of Co by Mn or Fe changes the easy magnetization direction from the basal plane to the c axis. Anisotropy fields were measured on magnetically aligned powders. The values for the anisotropy fields range between 12 and 24 kOe. Curie temperatures and saturation magnetization data for R2Co17−xTx compounds with T=Mn, Ru and R=Ho, Y are reported. The decrease of the magnetization with increasing x observed in the system Y2Co17−xTx is accounted for by assuming either a reduced Co moment or an antiparallel coupling of the T transition-metal spin. Similar considerations hold for Ho2Co17−xTx ternaries.