Optical, structural, and mechanical properties of different valence-cation-doped bismuth vanadate oxides

The optical, structural, and mechanical properties of Bi ₄V _{2 - x}M _xO _{11 - δ} (0 ≤ x ≤ 0.4 in the steps of 0.1, M = Mn, Ga, As) oxides have been investigated. The parameters like band gap (E _g), Urbach energy (E _u), grain size, hardness (H), and fracture strength (K) have been calculated as a function of dopant concentration, i.e., 0 ≤ x ≤ 0.4. In addition to this, the infrared spectra have been obtained for all the dopant oxides with different dopant concentrations. The results are discussed in light of correlation of these optical and mechanical parameters to their electrical properties. The fractured surface is analyzed by X-ray dot mapping to check the segregation of elements and their effect on mechanical properties.