Temperature dependence of thermodynamic and electrical properties of CuIrRhS4

• We study the thermodynamic and electrical properties of spinel CuIrRhS4.
• Electrical resistivity shows a metallic temperature dependence similar to that of A-15-type superconductor.
• Thermal conductivity has the contribution from the localized vibration hopping mode.
• Thermoelectric power by carrier diffusion shows a positive contribution.
• CuIrRhS4 has a dimensionless figure of merit of 0.0057 at 300 K.

We have investigated the thermodynamic and electrical properties of spinel CuIrRhS4. The temperature (T) dependence of the electrical resistivity (ρ  ) shows metallic behaviour defined as ∂ρ/∂T>0∂ρ/∂T>0, in the range of 5≤T≤300K. The T   dependence of thermal conductivity, κ(T)κ(T), has a broad peak resulting from the Umklapp process at 35 K and increases gradually above 80 K with increasing T  . κ(T)κ(T) can be reproduced by the combination of the usual Debye model and the localized-vibrations hopping model. Thermoelectric power, S(T), changes from negative to positive at 32 K and gradually increases with increasing T. The positive value of S(T) is due to carrier diffusion, which shows a hole-like band dispersion at the Fermi level. On the other hand, the negative value originates from phonon drag and variable-range hopping. We also estimated the T dependence of the dimensionless figure of merit, ZT  , from ρ(T),κ(T)ρ(T),κ(T), and S(T).