PHASE-EQUILIBRIA AT 1150-DEGREES-C IN THE CO-RICH ALLOYS SM-CO-ZR ANDSTRUCTURE OF THE 1 7 PHASE/

In the concentration range 75-100 at.% Co, the isothermal section at 1 150 degrees C of the system Sm-Co-Zr is determined experimentally. The following features are evidenced:a very small Sm solubility in Co, Zr 2Co11, and Zr6Co23, an extended Zr for Sm substitution rate in SmCo3, Sm2Co7 and Sm5Co19, and a significant Zr solubility in SmCo5 and Sm2Co 17 that induces the existence of a continuous ternary single phase 1:7 . On the basis of the lattice parameter data, the formation of this ph ase by the substitution of Co dumbbells and/or Sm atoms for Zr atoms i s proposed.