The possibility of ferromagnetic BCC ruthenium

Abstract

Band-structure calculations based on the augmented-plane-wave method and the rigid-band model are used to investigate the ferromagnetic 4d transition metals in the constrained crystal structure. The densities of states of 4d transition metals at the Fermi energy are estimated from those calculated for BCC and FCC Rh in paramagnetism. The results show that BCC Ru seems to be ferromagnetic using the Stoner criterion because of the high density of states. The band structure of Ru is studied in detail using the first-principles total-energy-band calculation by the Korringa-Kohn-Rostoker method based on the local-density approximation, whether ferromagnetic BCC Ru exists or not. It is concluded that BCC Ru has a magnetic moment of about 1mu B at 5% expanded lattice constant.