We report measurements on magnetization reversal in the Fe8 molecular magnet using fast pulsed magnetic fields of 1.5 kT/s and in the temperature range of 0.6-4.1 K. We observe and analyze the temperature dependence of the reversal process, which involves in some cases several resonances. Our experiments allow observation of resonant quantum tunneling of magnetization up to a temperature of ∼ 4 K. We also observe shifts of the resonance fields in temperature that suggest the emergence of a thermal instability---a combination of spin reversal and self-heating that may result in a magnetic deflagration process. The results are mainly understood in the framework of thermally-activated quantum tunneling transitions in combination with emergence of a thermal instability.
@article{arxiv.1403.2544,
title = {Spin reversal in Fe8 under fast pulsed magnetic fields},
author = {S. N. Jammalamadaka and J. Vanacken and V. V. Moshchalkov and Saül Vélez and J. Tejada and Ferran Macià},
journal= {arXiv preprint arXiv:1403.2544},
year = {2014}
}