Investigation of the superconducting state of ternary molybdenum sulfides

The properties of the superconducting state of bulk samples of ternary molybdenum sulfides containing copper, tin, and lead were investigated. The highest values of all three critical parameters T/sub c/, H/sub c/2, and J/sub c/ were observed in compounds with lead. Variation of the annealing temperature from 720 to 11200 C at one and the same annealing time (24 h) leads to a change in the density of the critical current in Pb/sub 1.2/Mo/sub 6.4/S8 samples by more than one order of magnitude, whereas the remaining critical parameters undergo changes in the range of 40%. The maximum critical-current density J/sub c/(140 kOe; 1.7 K) = 3.5 x 108 A/m2 is reached at an annealing temperature 9200 C. The connection between the shapes of the J/sub c/(H, T = const) curves and the damping rate of the critical current in hollow cylindrical samples is analyzed