Antiferromagnetic van der Waals family MPX3(M=Fe,Mn,Co, andNi;X=S andSe) have attracted significant research attention due to the possibility of realizing long-range magnetic order down to the monolayer limit. Here, we perform inelastic neutron scattering measurements on single crystal samples of MnPSe3, a member of the MPX3 family, to study the spin dynamics and determine the effective spin model. The excited magnon bands are well characterized by a spin model, which includes a Heisenberg term with three intraplane exchange parameters (J1=−0.73~meV, J2=−0.014~meV, J3=−0.43~meV) and one interplane parameter (Jc=−0.054~meV), and an easy-plane single-ion anisotropy term (D=−0.035~meV). Additionally, we observe the intersection of the magnon and phonon bands but no anomalous spectral features induced by the formation of magnon-phonon hybrid excitations at the intersecting region. We discuss possible reasons for the absence of such hybrid excitations in MnPSe3.
@article{arxiv.2406.05319,
title = {Spin and lattice dynamics of a van der Waals antiferromagnet MnPSe$_3$},
author = {Junbo Liao and Zhentao Huang and Yanyan Shangguan and Bo Zhang and Shufan Cheng and Hao Xu and Ryoichi Kajimoto and Kazuya Kamazawa and Song Bao and Jinsheng Wen},
journal= {arXiv preprint arXiv:2406.05319},
year = {2024}
}