Quasistatic magnetization evolution in the compensated ferrimagnetic half-metal Mn2RuxGa

Exploring anisotropy and diverse magnetization dynamics in specimens with vanishing magnetic moments presents a significant challenge using traditional magnetometry, as the low resolution of existing techniques hinders the ability to obtain accurate results. In this study, we delve deeper into the examination of magnetic anisotropy and quasistatic magnetization evolution in Mn2RuxGa (MRG) thin films, as an example of a compensated ferrimagnetic half-metal, by employing anomalous Hall effect measurements within a tetragonal crystal lattice system. Our research proposes an innovative approach to accurately determine the complete set of anisotropy constants of these MRG thin films. To achieve this, we perform anomalous Hall voltage curve fitting, using torque models under the macrospin approximation, which allow us to obtain room-temperature outof-plane anisotropy constants K1 = 4.0 x 104 J m-3 (K1/M = 0.655 T) and K2 = 2.54 x 104 J m-3 (K2/M = 0.416 T), along with a weaker in-plane anisotropy constant K3 = 3.48 x 103 J m-3 (K3/M = 0.057 T). By additionally employing first-order reversal curves and classical Preisach hysteresis (hysterons) models, we are able to validate the efficacy of the macrospin model in capturing the magnetic behavior of MRG thin films. Furthermore, our investigation substantiates that the complex steady-state magnetization behavior of MRG thin films can be effectively modeled using a combination of hysteronic and torque models. This approach facilitates the exploration of both linear and nonlinear steady-state magnetization evolution, in the presence of an external magnetic field and/or current-induced effective fields, generated by the spin-orbit torque and spin transfer torque mechanisms. The detailed understanding of the quasiequilibrium magnetization behavior is a key prerequisite for the exploitation of in-phase and out-of-phase resonance modes in this material class, for high-bandwidth modulators/demodulators, filters, and oscillators for the high-GHz and low-THz frequency bands.