Electronic structure and magnetism of the pseudo-binary compounds (Sc,Ca)Co2

A first principle band-calculation is carried out for pseudo-binary compounds (Sc1-xCax)Co2 with cubic Laves phase structure, in a self-consistent linear muffin-tin orbital method within the atomic sphere approximation. Sc and Ca are treated as virtual atoms with an atomic number, averaged over the concentration x. Three kinds of magnetic states of Co, large-moment and small-moment states and paramagnetic state, are found to exist in these compounds. A field-induced metamagnetic transition from the paramagnetic state to the small-moment one is shown to occur at x<0.09. The transition from the small-moment state to the large-moment one is also shown to occur at 0.09<x<0.15