High-conducting Bi4V1.8Cu0.2-xSbxO10.7+3x/2 ceramics: Structural, microstructural, electrical and optical properties

The partial substitution of copper by antimony in Bi4V1.8Cu0.2O10.7 compounds leds to the solid solution Bi4V1.8Cu0.2-xSbxO10.7+3x/2 (0.00 <= x <= 0.20). X-ray diffraction and thermal analysis showed that for all compositions, the obtained phases are isotype to the tetragonal gamma or gamma ' form of Bi4V2O11. The effect of Sb5+ doping on electrical conductivity was studied using electrochemical impedance spectroscopy in the temperature range 200-700 degrees C. The changes in slope observed in the Arrhenius plots correspond to the structural transitions that occur within the material. The band gap was determined by DRS spectra, BiCuSbVOx materials have a very low gap band (1.77-1.80 eV) compared to parent phase Bi4V2O11 and the most of BIMEVOX semiconductor materials. The band located around 860 cm(-1) in Raman spectroscopy is attributed to V-O bond and more especially to V-O-2 bond.

Automated summary

Partial substitution of copper by antimony in Bi4V1.8Cu0.2O10.7 compounds resulted in the formation of solid solution Bi4V1.8Cu0.2-xSbxO10.7+3x/2. The doping of Sb5+ affected the electrical conductivity and band gap of the material, as revealed by electrochemical impedance spectroscopy and DRS spectra.