Electronic Structure and Magnetic Properties ofSmCo7−xZrx

Abstract

The electronic structure and magnetism of SmCo7−xZrx alloyare investigated using the spin-polarized MS-X. method. The resultsshow that a few of electrons are transferred to the Sm(5d0) orbitaldue to orbital hybridization between Sm and Co atoms. The exchangeinteractions between 3d and 5d electrons are more important than thepolarization effects of the conductive electrons, thus it is the mainreason resulting in the long-range ferromagnetic order inSmCo7−xZrx. The Curie temperature of SmCo7−xZrx isgenerally lower than that of corresponding pure Co, which may beexplained by the weaker average coupling strength between Co latticesdue to some negative couplings mainly occurring of 2e site. Thecalculated results for the Sm5Co32Zr2 cluster may lead toa better understanding of why SmCo7−xZrx is stable phase. Sincethe spin-up DOS peak of d electrons at EF arises and the bondingof electrons at EF strengthens with increasing Zr concentration,which results in the internal energy of the system decrease, the stableferromagnetic order forms in SmCo7−xZrx.