Temperature Dependence of Resistivities in TiS₂ and Its Cu-Intercalate

Abstract

The electrical resistivities of a layered dichalcogenide TiS₂ and its Cu-intercalate were investigated in the temperature range 100 K to 350 K. The a-axis resistivity of the Cu-intercalate showed a linear temperature dependence rather than the T²-dependence reported in TiS₂. With increasing x in Ti_1+xS₂ and Cu_xTiS₂, both resistivities and their slopes decrease with temperature, while the carrier concentrations enlarge up to metallike orders of 10²² cm⁻³. This origin is discussed on a common basis of the slow transition from electron-electron to electron-phonon scatterings which is due to the increase of conduction electrons of the intercalated Cu metal as well as the self-intercalated Ti metal.