材料期刊网

The magnetic properties of Pr2Co17-x Al-x and Y2Co17-xAlx compounds with 0 less than or equal to x less than or equal to 4 were studied by means of magnetic measurements. These measurements have shown that increasing Al concentration leads to a sign reversal of the magnetocrystalline Co-sublattice anisotropy from easy-plane anisotropy for low Al concentration to easy-axis anisotropy for higher Al concentration. In the Pr2Co17-xAlx compounds, the competition between the Pr-and Co-sublattice anisotropies leads to spin-reorientation transitions at temperatures that decrease strongly with increasing Al concentration. There is an almost linear decrease of the Curie temperature with Al concentration. Also the saturation moments at 5 K decrease strongly with Al concentration although this decrease is less strong in Pr2Co17-xAlx than in Y2Co17-xAlx. (C) 1997 Elsevier Science S.A.