ac susceptibility study of magnetic relaxation phenomena in the antiskyrmion-hosting tetragonal Mn-Pt(Pd)-Sn system

摘要

Here, we report an exhaustive study of the frequency-dependent ac magnetic susceptibility of the D_(2d)symmetric Heusler system Mn-Pt(Pd)-Sn that hosts antiskyrmions over a wide temperature range. Magnetic relaxation studies using Cole-Cole formalism reveal a Debye-type relaxation with a nearly negligible distribution in relaxation times. In contrast to the archetypical skyrmion hosts, the high Curie temperature T_C of the present system ensures shorter switching times, and correspondingly, higher frequencies are required to probe the relaxation dynamics. We find a nonmonotonic variation in the characteristic relaxation time with distinct maxima at the phase boundaries via helical → antiskyrmion → field-polarized states, indicating slower magnetization dynamics over the region of phase coexistence. The temperature-dependent relaxation time across different phases is of the order of 10~(-5)- 10~(-4) s and follows the well-known Arrhenius law with reasonable values of the energy barriers. The present study concerning the magnetization dynamics in the antiskyrmion host tetragonal Heusler system is an important contribution towards the basic understanding of the dynamical aspects of antiskyrmions for their potential applications.