Effect on the Structure Stability of Minor Al or Zn Doping into SmCo7

We have synthesized SmCo7-xMx(M=Al, Zn; x=0, 0.1, 0.2, 0.3) alloys. Their phase structures of SmCo7-xMx alloys have been investigated using powder X-ray diffraction, and TREOR program has be used to index their characteristic diffraction peaks for determining the lattice parameters and cell volumes. The phase identifications show that SmCo7-xAlx(M=Al,Zn; x=0.1, 0.2, 0.3) alloys have the three phases. The main phase has Sm-Co 1:7 type structure and impurities phase are Sm2Co17 phase and unknown phase. It implies that the Al or Zn doping into SmCo7 does not stabilize the Sm-Co 1:7 phase and induces the phase separations. The planar indexing results reveal that the lattice parameters and unit cell volumes fluctuate with the increasing of Al or Zn content in SmCo7-xMx(M=Al, Zn; x=0, 0.1, 0.2, 0.3).