VARIATION WITH TEMPERATURE IN PHOTOPYROELECTRIC SPECTROSCOPY AND ELECTRICAL PARAMETERS OFZnO + 1.0 MnO2 + 0.8 Co3O4 + xBi2O3 + yTiO2 CERAMICS

Digest Journal of Nanomaterials and Biostructures

N. Nasir¹ 

关键词: Photopyroelectric spectroscopy;    Energy band gap;    ZnO;    Barrier height;   

DOI  :  

学科分类：生物技术

来源: Institute of Materials Physics

【 摘 要 】

Band gap energy (Eg) of doped ZnO ceramic with 1MnO, 0.8 Co3O4, xBi2O3 + yTiO2 where x = y = 0.6, 1 mol%. Different sintering times 1-4 hours have been studied in 300 to 800 nm wavelength range using a technique Photopyroelectric spectroscopy (PPES). The Graph is plotted between (ρhυ)2 and hυ. Eg is assessed from the plot which is about 2.03, 2.07 eV for the samples sintered for 2 hours at low and high doping levels, respectively. The increase in steepness factor (σA, in A-region and σB, in B-region) is related to sintering time at low and high doping level. Barrier height (ϕB) is 0.96, 0.89 eV for lower and higher doping level at 4 hour sintering time, respectively. The dielectric constant varied with the increases of sintering time. The dissipation factor Tanδ is decreased with the increase of sintering time. The X-ray diffractometry analysis shows that the crystal structure of ZnO doped with different MnO mol% remains to be of hexagonal type at all sintering times. Furthermore, it was observed that few feeble peaks are found related to the new phase Bi2MnTiO4, Zn2TiO4, MnTi4O4 and Bi4Ti3O12 at higher sintering time at both doping levels. The grain size ranges increased with the increase of sintering time and relative density decreased. Sintering time of the sample increases the density is decreased from (90.6, 88. to 88, 86 %) at lower and higher doping levels, respectively.

【 授权许可】

Unknown