Electronic structure of Gd pnictides calculated within the LSDA + U approach

摘要: A computational study of the electronic structure and magnetic properties Gd pnictides is reported. The calculations were performed using a full-potential linear muffin-tin orbital method within so-called $\mathrm{LSDA}+\mathrm{U}$ approach, which adds Hubbard-$U$ correlation effects to specified narrow bands in mean-field approach local spin-density approximation (LSDA). Here both $\mathrm{Gd}\phantom{\rule{0.3em}{0ex}}4f$ 5$d$ states are subject such corrections. ${U}_{f}$ values determined semiempirically by photoemission inverse data for $\mathrm{GdP}$, $\mathrm{GdAs}$, $\mathrm{GdSb}$, $\mathrm{GdBi}$. In contrast represents narrow-band physics, ${U}_{d}$ quasiparticle self-energy correction LSDA gap underestimate. value was adjusted optical-absorption semiconducting $\mathrm{GdN}$ above its Curie temperature. Below temperature, however, ferromagnetic state, becomes almost zero. other found have small overlap conduction band at $X$ point valence $\ensuremath{\Gamma}$ majority-spin channel. opens spin-minority channel $\mathrm{GdP}$ thus half metallic. This closes semimetallic $\mathrm{GdSb}$ While be ferromagnetic, antiferromagnetic, with ordering along [111]. From different configurations, Heisenberg model first second nearest-neighbor exchange parameters extracted. then used predict Curie-Weiss N\'eel temperatures critical fields mean field compared experimental data. trends good agreement