It was observed that the trapped magnetic moment of HTS tablets or annuli increases in time (negative relaxation) if they are not completely magnetized by a pulsed magnetic field. It is shown, in the framework of the Bean critical-state model, that the radial temperature gradient appearing in tablets or annuli during a pulsed field magnetization can explain the negative magnetic relaxation in the superconductor.
@article{arxiv.1206.0861,
title = {Negative magnetic relaxation in superconductors},
author = {E. P. Krasnoperov},
journal= {arXiv preprint arXiv:1206.0861},
year = {2015}
}