Molybdenum Trioxide Raman Spectrum

In general, molybdenum oxides are classified into two types: the metastable monoclinic β-MoO₃ phase and the thermodynamically stable orthorhombic α-MoO₃ phase. The latter kind, in particular, is an extremely promising oxide with structural anisotropy. The orthorhombic α-MoO₃ phase is a wide bandgap n-type semiconductor, which makes it a very attractive material for different technological applications. For example, it can be used as photochromic materials that change from colorless to blue by UV irradiation, smart windows, where Au nanoparticles improve the visible-light coloration performance of the MoO₃ thin film, self-developing photography, conductive gas sensors, lubricants, and catalysts.

Raman spectroscopy of MoO₃

Orthorhombic α-MoO₃ is composed of MoO₆ octahedral corner-sharing chains, with the edge shared by two similar chains to form the layers bonded by the weak van der Waals attraction. Thus, MoO₃ Raman spectra have 12 signature peaks related to stretching, bending, wagging, and twisting modes. The record of these peaks allows the evaluation of the sample quality. Hence, such an accurate and simple quality-control method makes the use of MoO₃ promising for various applications.