Fractional exponents of electrical and thermal conductivity of vanadium intercalated layered 2H-NbS₂ bulk crystal

Abstract

Intercalation of transition metal dichalcogenides (TMDs) by 3d or 4d transition metal elements are of considerable interest as the intercalated atoms can finely tune the physical and chemical properties of host TMDs. On addition, these intercalation complexes show interesting magnetic property and displays anomalous transport behavior at the magnetic ordering temperature. Here, we have synthesized and measured transport properties of single crystal vanadium intercalated Niobium Di-sulphide. At 300 K, electrical resistivity and thermal conductivity of V$_{0.3}$NbS$_{2}$ is found to be $\sim$ 10$^{-6}$ $\Omega$ m and 36 W m$^{-1}$ K$^{-1}$ respectively. Unlike phonon scattering, the spin scattering is found to affect both electrical and phonon conduction at low temperature. The electrical resistivity at temperature ${T} < 45\,\hbox {K}$ follows $T^{3/2}$ behavior, whereas the electronic part of thermal conductivity shows exponent of 0.8. Using steady-state method, the temperature dependent lattice part of thermal conductivity shows exponents of 0.5 and − 0.5 at ${T} < 45\,\hbox {K}$ and ${T} > 45\,\hbox {K}$ respectively. Moreover, the peak of the total thermal conductivity also overlaps with the magnetic transition temperature, indicating the participation of spin dependent phonon dynamics below 45 K.