Synthesis, transport and superconducting properties of rare earth metal intercalated tantalum disulfide RExTaS2 (RE=La,Ce)

The new intercalated systems RExTaS2 (RE=La,Ce) were prepared and their transport and superconducting properties were investigated. Different preparation methods provided four phases (α, β, γ and δ) which could be classified according to their structure forms. The temperature dependence of the resistivity had a minimum at 35 K and 23 K for La and Ce intercalated samples (phase γ), respectively. By the AC susceptibility measurement, the superconductivity was detected in La.16TaS2 (phase α) and Ce intercalated sample (phase δ). A large parametric signal was observed in the latter compound above the transition temperature 1.7 K. (orig.)