First-principles survey on the doping of Ga in Nd2Fe14B

The preferential site substitution of Fe by Ga and its effect on magnetic moments have been studied in Nd2Fe14B by a first-principles density functional calculation. The calculated substitution energies of Ga are positive values and unfavorable for the Ga substitution at the sites of 8j2, 16k1, and 4e, while those are negative values and favorable for the Ga substitution at the sites of 4c, 8j1, and 16k2, in good agreement with the experimental results. The Ga atom shows a small induced negative moment with a size of about 0.2 μB. The magnetic moments of Fe with the nearest neighbor of Ga reduce by about 0.1–0.2 μB while the moments of Nd with the Ga nearest neighbors are enhanced slightly. These magnetic moment changes originate from the hybrid of the Ga 4p- with the Fe 3d- or the Nd 5d-electron states.