Magnon-phonon coupling modulation via dimensional reduction in thin antiferromagnet MnPSe₃ nanoribbons

Two-dimensional (2D) magnetic materials have triggered tremendous interest in recent years due to their remarkable potential applications in magnetic storage and spintronics devices. Heat dissipation is of great significance in stability and durability of increasingly integrated magnetic devices. However, little investigation of thermal transport has been carried out in 2D magnetic materials and a comprehensive understanding of the underlying mechanism is still lacking. We experimentally demonstrate the thermal conductivity measurement of MnPSe₃ nanoribbons and find a nonmonotonic thickness dependence, which is attributed to the phonon confinement effect in thin nanoribbons. The peaks of measured thermal conductivity are found to be modified with increasing thickness due to the magnon-phonon coupling. We propose that the magnon-phonon scattering rate increases with increasing thickness and causes a huge suppression in thermal conductivity. This study will deepen the understanding of the thermal properties of 2D magnetic materials and will benefit thermal management in designing magnetic devices.