Growth and anisotropy evaluation of NbBiCh3 (Ch = S, Se) misfit-layered superconducting single crystals

Abstract NbBiCh3 (Ch = S, Se) misfit-layered superconducting single crystals were successfully grown using a CsCl/KCl flux for the first time. The obtained crystals had a well-developed habit parallel to the c-plane with a typical width of 1–2 mm and thickness of 10–40 μm. The superconducting transition temperatures with zero resistivity of NbBiS3 single crystals obtained from the nominal composition of Nb0.9Bi1.2S3 was 0.31 K, and that value of the NbBiSe3 single crystals grown from the stoichiometry composition (NbBiSe3) was 2.3 K. Sharp decreases in electric resistivity and magnetic susceptibility at approximately 3 K suggested a possible superconducting transition temperature of NbBiSe3. The normal-state anisotropy values of grown NbBiS3 and NbBiSe3 single crystals were 2.2–2.4 and 1.5–1.6, respectively.