Synthesis and properties of a new superconducting compound (ZrNixS2)

Since the discovery of superconductivity in chalcogenides in Fe-Se system and in iron pnictides much attention have been give for synthesis of new materials which can exhibit superconductivity. Within this context in this work we show results which suggest that ZrNi$_{x}$S$_{2}$, where x can assume 0.3, 0.5 and 0.8 values, is a new superconductor material. This compound crystallizes in a new crystallographic structure with hexagonal symmetry belongs to the space group R -- 32/m. Indeed this compound is a variation of the Zr$_{3}$S$_{4}$ which can be considered as the prototype structure of this new compound (ZrNi$_{x}$S$_{2}$). In this prototype structure zirconium atoms may occupy two different sites in the structure. Thus, nickel atoms substitute zirconium in a specific site of the structure. These results suggest that superconducting critical temperature is dependent of the nickel content in this new compound. The optimum Ni content yield to T$_{c}$ $\sim$ 9.8 K.