Layer-dependent Raman spectroscopy study on two-dimensional van der Waals antiferromagnetic semiconductor MPS3 (M=Fe, Mn)

MPS3 is a typical two-dimensional layered material. For the sake of expanding its application value as layered structure, the better understanding of the layer-dependent properties and interlayer coupling of MPS3 is of great significance. These properties can also vary with different transition metal atom. Here, this issue was addressed through the detailed research on two typical compounds FePS3 and MnPS3, by Raman spectroscopy. It is found that the characteristic Raman peaks shift weakly as layer number decreasing, confirming the relative stability of layer-dependent properties both for FePS3 and MnPS3. By further quantitative analysis on Ag3 and Ag4 peaks together with their relative intensity and linewidth ratios, we found that these two peaks of FePS3 have greater change than MnPS3 with decreasing layer numbers, either in wavenumber or in linewidth. Such results indicate FePS3 may has stronger interlayer coupling than MnPS3, and its layer-dependent vibration properties are more susceptible to layer numbers.