Effects of Carrier Doping into the Misfit-Layer Compounds (La_{1- y}R_yS)_{1+ α}VS₂(R=Sr and Pb): Transport and Magnetic Studies

Transport and magnetic measurements including the magnetic resonance of V-51 nuclei have been carried out for misfit-layer compounds (La(1-y)R(y)S)(1+alpha)VS2 (R = Sr and Pb, 0 less than or equal to y less than or equal to 1.0). The results indicate that the system is in the Mott insulating state at high temperatures, at least in they region near alpha/(1 + alpha) which corresponds to the V-valency of +3. It undergoes a transition with decreasing temperature possibly to a nonmagnetic ground state. With increasing carrier doping into this insulating state, the system tends to become metallic and an essentially metallic state is realized in the hole-doped region 0.30 less than or similar to x = y(1 + alpha) < 0.5, where various properties are found to exhibit anomalous behavior similar to the case of high-T-c Cu-oxides.