Crystal and electronic structures, transport properties of a ternary tungsten silicophosphide W3Si2P

Abstract

Here we report a tungsten silicophosphide W3Si2P isostructural and isoelectronic to Mo3Si2P, which was prepared by heating the constituent elements at 1170 °C. It adopts a nonsymmorphic lattice with a-glide symmetry (noncentrosymmetric space group Ama2). The electrical and thermal transport properties were characterized by electrical resistivity, Seebeck effect and thermal conductivity (κ). W3Si2P shows metallic conduction following the Bloch-Grüneisen-Mott model with holes as the main carriers, which is also supported by ab-initio calculations. Electronic and lattice κ make comparable contributions to the thermal conduction at high temperatures, while the electronic component dominates at low temperatures. Electronic-structure calculations reveal that the W 5d orbits govern the bands near the Fermi level, in which 5dx2−y2 orbital electrons take the maximal occupation. As the first genuine ternary compound in W–Si–P family, it might be a novelty playground to probe the underlying electronic physics related to crystallographic symmetry. A tabulation summarizes the compounds in W–Si–P system, and reviews on their structural and physical properties were made to build a comprehensive understanding of this system.