Low-temperature jump-like strains on different scales in the normal state of Pb-(4−49) at. % In alloys

The instability of plastic flow in Pb-(4−49) at. % In alloys with different amplitude scales during deformation in the normal state at a temperature of 1.65 K is studied. The dependences of small- (∼0.1 MPa) and large-amplitude (∼1 MPa) stress jumps and of their concentrations on the degree of deformation of the polycrystals, their indium content, and the sample thickness are determined. The influence of jump-like deformation on the softening of the alloys during the transition from the normal to the superconducting state is examined. The controlling mechanism for this phenomenon is discussed.