Temperature rise in an Sm-based bulk superconductor after applying iterative pulse fields

The time evolutions and spatial distributions of temperature rise Δ T ( t ) have been measured on the surface of a cryo-cooled SmBaCuO bulk superconductor after iterative pulse field magnetizing with the same amplitude. For the applied pulse field B ex ⩽ 4.64 T, the maximum temperature rise Δ T max monotonically decreases and approaches a steady Δ T ( t ) behaviour with an increasing number of times of pulse applications. On the other hand, for B ex = 5.42 T, Δ T max keeps on increasing after the third pulse application in a specific growth sector region and a clear anisotropic Δ T ( t ) behaviour has been found. The magnetic fluxes preferentially enter and leave the bulk superconductor through this sector region. The Δ T ( t ) behaviours are closely correlated with the distribution of the trapped field B T P and can be understood on the basis of the heat generation caused by the flux motion.