Transport properties of self-intercalated compounds Ti1-xS2

Our initial attempt to obtain zero-gap layered crystals from semiconducting TiS2 and semimetallic TiTe2 by the chemical vapor transport method leads to the growth of heavily self-intercalated crystals of Ti1+xS2 (x = 0.20-0.33). Here we shall show how the degree of self-intercalation in TiS2 crystal is changed by the growth conditions and the results of resistivity, Hall effect, and thermopower measurements for Ti1+xS2 over the temperature range 1.6-300 K, whose electronic properties can be understood in terms of the two-carrier model of electrons and holes.