ELECTRONIC AND MAGNETIC-STRUCTURES OF THE RARE-EARTH PERMANENT-MAGNETND2FE14B

Electronic and magnetic structures of Nd2Fe14B are investigated by per forming self-consistent local-density-approximation band-structure cal culations and photoemission-spectroscopy (PES) measurements. Employing the linear muffin-tin-orbital band method, we have obtained electroni c band structures for both paramagnetic and ferromagnetic phases of Nd 2Fe14B, and compared the calculated density of states (DOS) with the e xperimental data obtained from PES measurements. It is found that B at oms contribute to the stabilization of the structure and substantially reduce the magnetic moment of neighboring Fe atoms through a hybridiz ation interaction. The average magnetic moment of Fe atoms in the ferr omagnetic phase is estimated to be 2.15 mu(B). Depending on the distan ces from B atoms, Fe atoms at the j2 site and those at the e site have the largest and smallest magnetic moments, respectively, in qualitati ve agreement with the experimental trend. The valence-band PES measure ments for Nd 4f states indicate that the Nd valence is close to trival ent, with negligible Nd 4f spectral intensity close to E(F), which is consistent with the observed trivalent Nd 4f magnetic moments in this compound. The line shape of the Nd 4f PES is broader than that of pure Nd metal, reflecting effects of the hybridization between Nd 4f and F e 3d electrons. The Fe 3d PES spectrum shows that the Fe 3d electrons mainly determine the DOS near E(F). The calculated Fe 3d projected loc al density of states agrees reasonably well with the Fe 3d PES spectru m, which implies that the Fe 3d magnetism in Nd2Fe14B may well be unde rstood in terms of the itinerant magnetism of Fe 3d electrons.