Research on the Superconducting Properties of Transition Metal Sulfide Compounds

The purpose of this study was to investigate the influence of electron vacancies on the superconducting properties of transition metal sulfide compounds (Cr, Cu) to evaluate their potential in increasing the critical transition temperature. This study reviewed the theoretical models and experimental data on superconductivity based on copper, chromium, and sulfide compounds. Synthesis and stability data for the FeCuS2 compound were used for analysis, and temperature coefficients for various superconducting materials, including oxides and sulfides, were calculated. The study considered the compound Fe2Cu3S6, which exhibited superconductivity at 89 K, with a narrow transition interval and evidence of ferromagnetic ordering. Experimental data indicated the influence of electron vacancies in the crystal lattice on conductivity, which favors the occurrence of the superconducting state. Model calculations revealed a linear dependence between the number of electron vacancies Qelv and the transition temperature Tc in a series of sulfide systems, including Cr-Cu-S. This gives prospects for the search for superconductors with high transition temperatures. Comparison with other materials, such as oxide compounds, revealed that sulfides can exhibit greater critical superconductivity temperatures. The practical significance of the study lies in the development of new approaches to the design of sulfide compounds that promote the generation of a superconducting state at room temperatures.