Preparation and chemical characterization of neodymium-doped molybdenum oxide films grown using spray pyrolysis

Abstract

We studied the crystallinity, morphology, and surface composition of Nd-doped molybdenum oxide films grown on glass slides through spray pyrolysis. After fabrication, the films were subjected to thermal treatment in oxygen for periods ranging from 2 to 20 hours. The films were structurally characterized through X-ray diffraction (XRD), their bulk chemical composition was determined using Energy-Dispersive X-ray analysis (EDX), and their surface composition was determined using X-ray Photoelectron Spectroscopy (XPS). The XRD results show that the films obtained from different dissolution volumes and at substrate temperature of 300$^{\circ}$ C exhibit the characteristics of the oxygen-deficient molybdenum trioxide Mo$_{9}$O$_{26}$ phase. The films subjected to different thermal treatments exhibit a mixture of Mo$_{9}$O$_{26}$ and Mo$_{17}$O$_{47}$ phases. EDX study shows the energy belonging to the L line of Nd. Finally, films doped with Nd and subjected to a thermal treatment of 20h were analyzed through XPS, showing the binding energies at the crystalline lattice correspond to Nd$_{2}$ (MoO$_{4}$)$_{3}$ and Nd$_{2}$Mo$_{2}$O$_{7}$.