Anharmonic phonon scattering study in MnPS3 crystal by Raman spectroscopy

Phonons play a vital role in lattice dynamics, so a better understanding of anharmonic phonon scattering in van der Waals material MnPS3 is of great significance for its potential applications. Here, we employed Raman spectrum, in situ x-ray diffraction, and first-principles calculations for detailed research. The volume thermal expansion coefficient of MnPS3 was reported. Through the symmetric phonon scattering model, it is confirmed that cubic phonon processes play a major role in P2, P3, P4, and P5 peaks, while quartic phonon processes play an indispensable role in most peaks. The covalent bond was found to be more susceptible to anharmonic phonon scattering than ionic bonds, which is reflected in the wavenumber redshift. Moreover, asymmetric phonon scattering channels also play a meaningful role. Different cubic phonon scattering channels greatly influence the fitting results, and various quartic phonon scattering channels are diverse in highly nonlinear linewidth broadening.