ELECTRONIC-STRUCTURE AND MAGNETIC-PROPERTIES OF COTI1-XALX ALLOYS

Abstract

The band structure of ordered CoTi, CoAl and Co2TiAl alloys is calculated by the spin-polarized TB LMTO method. We do not observe a magnetic moment on the Co atom in CoTi and CoAl compounds with the CsCl type structure. The Co2TiAl alloy with the L2(1) type structure is ferromagnetic with a magnetic moment on the Co atom m(Co) = 0.27 mu(B) and a small opposite induced magnetic moment on the Ti atom m(Ti) = -0.05 mu(B). The electronic densities of states of the disorder CoTi1-xAlx alloys are computed by the TB LMTO CPA method. We find that the magnetic moment has the maximum for x = 0.5 and it decreases to zero for x = 0 and x = 1.0. From the values of the density of states at the Fermi level we calculate the electronic specific heat coefficient gamma. The general trend of gamma is close to the experimental data.