In-plane anisotropic optical and mechanical properties of two-dimensional MoO3

Molybdenum trioxide (MoO3) in-plane anisotropy has increasingly attracted the attention of the scientific community in the last few years. Many of the observed in-plane anisotropic properties stem from the anisotropic refractive index and elastic constants of the material but a comprehensive analysis of these fundamental properties is still lacking. Here we employ Raman and micro-reflectance measurements, using polarized light, to determine the angular dependence of the refractive index of thin MoO3 flakes and we study the directional dependence of the MoO3 Young's modulus using the buckling metrology method. We found that MoO3 displays one of the largest in-plane anisotropic mechanical properties reported for 2D materials so far.

Automated summary

The in-plane anisotropy of molybdenum trioxide (MoO3) has attracted increasing attention from the scientific community, with observed properties stemming from the material's anisotropic refractive index and elastic constants. Raman and micro-reflectance measurements were used to determine the angular dependence of the refractive index of thin MoO3 flakes, while the directional dependence of the MoO3 Young's modulus was studied using the buckling metrology method. It was found that MoO3 exhibits one of the largest in-plane anisotropic mechanical properties reported for 2D materials.