The Heusler-type compound of ${\mathrm{Ru}}_2\mathrm{NbGa}$ has been successfully synthesized. X-ray analysis confirms that ${\mathrm{Ru}}_2\mathrm{NbGa}$ crystallizes in a cubic $L{2}_1$ structure. The electronic properties of ${\mathrm{Ru}}_2\mathrm{NbGa}$ have been characterized by means of the transport and nuclear magnetic resonance (NMR) measurements. The temperature dependence of the electrical resistivity exhibits a typical semimetallic behavior. The NMR spin-lattice relaxation rate shows activated behavior at higher temperatures, attributing to the thermally excited carriers across a pseudogap. We have also deduced a low Fermi-level density of states (DOS), being consistent with the semimetallic characteristic for ${\mathrm{Ru}}_2\mathrm{NbGa}$. In addition, we have performed first-principles total-energy calculations including $G_0{W}_0$ and $G{W}_0$ corrections for band gaps to investigate the electronic band structure of ${\mathrm{Ru}}_2\mathrm{NbGa}$. The calculated result reveals an indirect overlap between electron and hole pockets that leads to a residual DOS at the Fermi level, providing a consistent explanation for the experimental observations.

• Received 30 August 2016
• Revised 17 October 2016

DOI:https://doi.org/10.1103/PhysRevB.94.205116