Effect of Cr Doping on the Structural, Optical and Dielectric Properties of MoO3 Microrods Synthesized by Sol-Gel Auto Combustion Method

In the present work, pure and Cr-doped MoO3 microrods were successfully prepared through the sol gel auto combustion method. The phase evaluation and microstructural, dielectric, and optical properties of synthesized samples were investigated by using X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and an impedance analyzer (1 MHz-3 GHz). All the samples showed hexagonal structure with space group (P63). According to Vegard's law, lattice parameters increase with the increase in chromium (Cr3+) contents. In addition, the Williamson-Hall (W-H) plot was drawn for evaluating the micro-strain (epsilon(W-H)) and crystallite size (DW-H) parameters. From microstructural analysis it was found that the size of microrods increased along with Cr3+ contents. Decreasing band gap energy was observed (from 2.98 to 2.71 eV) with increasing Cr3+ contents. The variation of the dielectric constant and tangent loss of MoO3 microrods with respect to frequency were analyzed.