Photopyroelectric spectroscopic studies of ZnO-MnO 2-Co 3O 4-V 2O 5 ceramics

Abstract

Photopyroelectric (PPE) spectroscopy is a nondestructive tool that is used to study the optical properties of the ceramics (ZnO + 0.4MnO 2 + 0.4Co 3O 4 + xV 2O 5), x = 0-1 mol%. Wavelength of incident light, modulated at 10 Hz, was in the range of 300-800 nm. PPE spectrum with reference to the doping level and sintering temperature is discussed. Optical energy band-gap (E g) was 2.11 eV for 0.3 mol% V 2O 5 at a sintering temperature of 1025 °C as determined from the plot (ρhυ) 2 versus hυ. With a further increase in V 2O 5, the value of E g was found to be 2.59 eV. Steepness factor 'σ A' and 'σ B', which characterize the slope of exponential optical absorption, is discussed with reference to the variation of E g. XRD, SEM and EDAX are also used for characterization of the ceramic. For this ceramic, the maximum relative density and grain size was observed to be 91.8% and 9.5 μm, respectively. © 2011 by the authors; licensee MDPI, Basel, Switzerland.