The microstrain-accompanied structural phase transition from h-MoO₃ to α-MoO₃ investigated by in situ X-ray diffraction.

ABSTRACT: In situ X-ray diffraction indicates that the structural phase transition from h-MoO₃ to α-MoO₃ is a first-order transition with a phase transition temperature range of 378.5-443.1 °C. The linear coefficients of thermal expansion of h-MoO₃ are strongly anisotropic, that is, α_a=b = 72.87 × 10^-6 K^-1 and α_c = -19.44 × 10^-6 K^-1. In the h-MoO₃ phase, water molecules are located at the (0 0 0.25) site inside the MoO₆ octahedra tunnel that is formed by six MoO₆ corner-sharing octahedron zigzag chains. With increasing temperature, the release of water molecules from the octahedra tunnel causes the octahedra chains to shrink an

SUBMITTER: Zhang Z 

PROVIDER: S-EPMC10280079 | biostudies-literature | 2023

REPOSITORIES: biostudies-literature