Analysis of the crystal phase and orientation of nanocrystals and nanorods of MoOx thin films

Abstract

Nanoscale materials, which are also known as nanomaterials, have attracted considerable attention owing to their unique physical properties and discrete band structures. Recently, studies have focused on the enhanced chemical reactions of nanomaterials with large specific surface areas for several applications, such as gas sensing. In this study, we investigated the orientation of MoOx nanorods and plate-like crystals constituting molybdenum oxide nanostructured thin films by transmission electron microscopy and three-dimensional X-ray diffraction. The nanorods are composed of Mo8O23 (non-stoichiometric composition) and are elongated along the b-axis, although they are developed in random directions with respect to the substrate. The plate-like crystals comprise α-MoO3 and they are strongly oriented along the 0k0 plane horizontally to the substrate surface. Thus, the crystal structure and orientation of individual components of MoOx nanostructured thin films are clarified via transmission electron microscopy and three-dimensional X-ray diffraction studies.