Spin-Phonon Coupling on 2D NiPS₃ Nanosheets: Implications for Antiferromagnetic Spintronic and Spin Caloritronic Devices

The spin-phonon coupling (SPC) effect is one of the most important interactions that provides a powerful tool for advancing 2D spintronic devices. 2D NiPS 3 stands out from the synthesized 2D magnets because it is an XY-type antiferromagnet semiconductor with the highest Néel temperature. In this work, we investigate the SPC effect on 2D NiPS 3 nanosheets by examining the thermal transport properties linked to the magnetic order and the magnetic properties influenced by strain. Our findings reveal the significant variation of magnetic ordering on phonon vibrations. Remarkably, the spin-phonon coupling constant is measured to be 29.85 cm –1, which is 1 order of magnitude greater than that of most other 2D magnets. We discovered that the formation of long-range antiferromagnetic order in NiPS 3 notably boosts the lattice thermal conductivity, with increases of 736.54% at 10 K, 32.95% at 150 K, and 31.41% at 300 K. The enhancement in thermal conductivity in the AFM NiPS 3 nanosheets predominantly originates from the phonon lifetime and phonon anharmonicity. Moreover, taking advantage of the SPC effect, we also observe that the XY-type AFM is suppressed under the tensile strain. This study not only contributes to a better understanding of the interplay between lattice and spin degrees of freedom in the 2D limit but also holds promise for the development of high-efficiency thermal management and spin Seebeck devices.