Effect of TiO 2 doping on structural and electrical properties of melt-quench V 2−x Ti x O 5−δ , 0.15 ≤ x ≤ 0.30 systems

Compositions of V2−xTixO5−δ (x = 0.15, 0.20, 0.25, and 0.30) are synthesized by the melt-quench technique. Different experimental techniques are used to study structural, optical, thermal, and electrical properties. Various physical parameters are also calculated using apparent density to support the conduction mechanism of the prepared samples. X-ray diffraction (XRD) is confirmed the formation of orthorhombic V2O5 phase. The doping of TiO2 supports the transfer of VO5 structural units into VO4 units as confirmed by Fourier transform infrared (FTIR) and Raman spectroscopy. The optical band gap (Eg) and Urbach energy (EU) of the TiO2-doped vanadium samples are obtained with the help of diffused reflectance spectra (DRS). A marginally decreasing trend in the optical band gap (2.28–2.20 eV) is observed with dopant content. X-ray photoelectron spectroscopy measurement is confirmed that vanadium is present in mixed state, i.e., V5+ and V4+ which leads to the increase in conductivity of the doped samples. The highest DC conductivity is observed about 1.12 S m−1 at 400 °C.