Effects of spin-wave excitations in half-metallic materials

Finite-temperature magnetic properties of half-metallic materials are investigated on the basis of the first-principles Korringa-Kohn-Rostoker Green's function method. Influences of spin-wave excitations on the electronic structure are examined in the framework of the coherent potential approximation. The calculations show that the half-metallicity is easily destroyed due to an appearence of low-energy electron excited states in the minority-spin band gap at finite temperature. On the other hand, calculated dc conductivity shows that the 100% spin-polarized conduction occurring in half-metallic materials hardly deteriorates even in such a temperature.