MAGNETIC-PROPERTIES OF CO(1-X)M(X)PT(3) (M=MN, FE) COMPOUNDS WITH COMPETING INTERACTIONS

Magnetic properties of the pseudo-binary Co(1-x)M(x)Pt(3) (M = Mn, Fe) compounds have been investigated. Under adequate preparation conditio ns, these compounds display the L1(2) structure. For M = Mn the magnet ic phase diagram presents a continuous ferromagnetic region from CoPt3 to MnPt3 with a re-entrant spin glass (RSG) phase emerging at low T a nd H between x = 0.2 and 0.6. For M = Fe, a spin glass (SG) phase sepa rates the ferromagnetic region on the Co-rich side, from the antiferro magnetic region on the Fe-rich side. The results are qualitatively dis cussed in terms of the three dominant competing magnetic interactions J(CoCo), J(CoM), J(MM).