2023/09/20 by Hong, Liangliang, Xu, Changsong, Xiang, Hongjun · 2 citations
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.2309.11152
Magnetic damping has a significant impact on the performance of various magnetic and spintronic devices, making it a long-standing focus of research. The strength of magnetic damping is usually quantified by the Gilbert damping constant in the Landau-Lifshitz-Gilbert equation. Here we propose a first-principles based approach to evaluate the Gilbert damping constant contributed by spin-lattice coupling in magnetic insulators. The approach involves effective Hamiltonian models and spin-lattice dynamics simulations. As a case study, we applied our method to Y3Fe5O12, MnFe2O4 and Cr2O3. Their damping constants were calculated to be 0.8×10-4, 0.2×10-4, 2.2× 10-4, respectively at a low temperature. The results for Y3Fe5O12 and Cr2O3 are in good agreement with experimental measurements, while the discrepancy in MnFe2O4 can be attributed to the inhomogeneity and small band gap in real samples. The stronger damping observed in Cr2O3, compared to Y3Fe5O12, essentially results from its stronger spin-lattice coupling. In addition, we confirmed a proportional relationship between damping constants and the temperature difference of subsystems, which had been reported in previous studies. These successful applications suggest that our approach serves as a promising candidate for estimating the Gilbert damping constant in magnetic insulators.