ИСТИНА

The scientific interest in compounds of the structural type IrIn3 (tetragonal, P42/mnm) arose due to their promising thermoelectric properties. According to the literature the thermoelectric activity of IrIn3-type compounds is highly associated with the features of their band structure. In these compounds, a gap near the Fermi level is created by the strong hybridization of the d-orbitals of transition metal and the s, p orbitals of post-transition element. Since the type of conductivity depends on the concentration of valence electrons, FeGa3, RuGa3, RuIn3 and OsGa3 possessing 17 valence electrons are semiconductors. An increase in number of valence electrons to 18 leads to the metallic properties of CoGa3, CoIn3, RhIn3 and IrIn3. RuGa3 has a high Seebeck coefficient of 560 μ/ K at 373 K, the Seebeck coefficient of RuGa3 quickly changes from large negative to large positive values around 500 K, and the thermoelectric figure of merit ZT = (S2/ρκ)T reaches a maximum value of 0,17 at 773 K. However, high electrical resistivity and thermal conductivity reduce the thermoelectric figure of merit. The purpose of this work is to study RuGa3 by means of nuclear quadrupole resonance (NQR) spectroscopy and to analyze the temperature dependence of the spin-lattice relaxation rate 1/T1.