Transport and optical properties of the hydrazine intercalation complexes of 1T-TaS2

Abstract
The reversible interconversion of 1T-TaS2 with the hydrazine complexes 3R1.1 TaS2(N2H4)4/3 and 3RI TaS2(N2H4)2/3 has been studied by thermogravimetric analysis, optical transmission, and electrical resistivity measurements. The low-temperature resistivity of both hydrazine complexes is high, exceeding 103 Omega cm when below 20K, and for the 3RI.I complex in rho varies as T-1/3. This can be interpreted as two-dimensional variable range hopping at the Fermi level, EF, in a system in which the density of states at EF is reduced from the expected metallic value by the presence of a strong Fermi-surface driven structural distortion.