ELECTRONIC-STRUCTURE AND MAGNETISM OF C15-TYPE LAVES PHASE-COMPOUNDS Y(CO, AL)2 AND Y(CO, SI)2

Electronic structures of the binary compound YCo2 and the ordered ternary compounds Y(Co1-xAlx)2 and Y(Co1-xSix)2 with the cubic Laves structure are calculated within the density functional theory. It is shown that the magnetic properties observed in the recent experiments, such as induced weak ferromagnetism and metamagnetic transitions, can be qualitatively explained by using the calculated results of the density-of-states curves. The role of the p-d hybridisation is discussed.