Exploration Of New Bi-S Layer Superconductors And The Fe-doping Effect On Superconductivity Of K_0.8Fe_1.75Se₂

With a large number of reports being published on the iron-based and BiS2-basedsuperconductors in recent years, research on new types of high temperaturesuperconducting attracts much attention. Searching for new superconductors with highcritical transition tempertature Tcand understanding the superconducting machenismare two major leading issues. This article explores and summarizes the Fe doping effectof different elements on K0.8Fe1.75Se2and the synthesis of new layer BiS2superconducting materials by replacing the superconducting layer or block layer withdifferent elements. The structure and properties of the samples were studied.1. Polycrystalline samples of LaOSbS2were synthesized via solid reaction methodand the structure and physical properties were investigated by XRD, SEM, PPMS.2. Polycrystalline samples of LaOSbSe2were synthesized by replacing the S inBiS2layer with Se, and the structure and physical properties were investigated by XRD,SEM, TEM, PPMS.3. Single crystal samples of K0.8Fe1.75-xMxSe2(M=Cu, Ni, Mn, Zn, Co, Cr), weresynthesized by flux method and the doping effect on microstructure were investigatedby SEM and TEM.