Softening of the flux-line structure in La 1.8 - Sr 0.2 - CuO 4 measured by a vibrating reed

Abstract

Vibrating reed measurements in La 1.8 - Sr 0.2 - CuO 4 in a magnetic field show that the flux-line structure (FLS) becomes uncoupled from the material at a temperature Th of 23K, much below the critical temperature of the sample which is 32K.