Effect of γ -Irradiation and Calcination Temperature of Nanosized ZnO/TiO 2 System on Its Structural and Electrical Properties

ZnO/TiO 2 powders were synthesized by sol-gel method using ammonium hydroxide. The effects of calcination temperature (500–1000°C) and gamma rays (with doses from 25 to 150 kGy) on the phases present and their electrical properties were investigated. The results revealed that heating the system investigated at 500°C led to the formation of ZnTiO 3 -rohom and TiO 2 -rutile. The degree of crystallinity of the phases produced increased by increasing the calcination temperature. When heating at 1000°C, ZnTiO 3 -rohom turned to ZnTiO 3 -cubic but the rutile phase remained stable. γ -Irradiation decreased considerably the crystallite size of the rutile phase from 146 to 63 nm and that of ZnTiO 3 -cubic decreased from 101 to 39 nm. This treatment led also to the creation of holes in the matrix of irradiated solids which increased the mobility of charge carriers (electrons) leading to a significant increase in the electrical conductivity reaching to 10 2 to 10 3 -fold.