Strain-induced simultaneous modulation of ferromagnetism and lattice thermal conductivity in 2H-VS2

Two-dimensional (2D) bipolar magnetic semiconductors (BMS) are rare materials with purely spin-polarized band edges that also host correlated electronic states, intrinsic magnetism, and tunable phonon transport. These properties make them attractive for spin field effect transistors, ambient thermoelectric energy harvesting, spin-caloritronics, and flexible thermal management, where precise control over magnetic ordering and lattice thermal conductivity is essential. Here, we investigate the strain-dependent coupling between magnetic and thermal degrees of freedom in the BMS monolayer 2H-VS 2 . We demonstrate that equi-biaxial tensile strain simultaneously modulates magnetic ordering and lattice thermal conductivity: a monotonic decrease in the Curie temperature (~50 K at 5% strain) due to weakened superexchange, paired with a ~ 22% suppression of lattice thermal conductivity. This thermal suppression originates from a four-fold increase in the Grüneisen parameter (0.26 → 0.97), which significantly enhances phonon anharmonicity and three-phonon scattering. Phonon mean-free-path analysis further reveals a saturation length of ~25 nm, providing practical guidelines for grain-size engineering. Overall, this work establishes mechanical strain as a powerful unified control parameter for coupled spin-lattice-thermal properties, offering design principles for the development of strain-engineered 2D materials in energy harvesting, thermal management, and spin-caloritronic devices operating in the near-room-temperature to cryogenic regime.