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ZnO/TiO2 composite ceramics have been prepared by solid-state reaction technique at 900°C. The X-ray diffraction results revealed the formation of secondary phases referred to as spinel Zn2TiO4 and hexagonal ZnTiO3. The structural analysis showed that all the composites that have been prepared have a polycrystalline nature and a hexagonal wurtzite structure. The complex modulus ( M) and electric impedance of the samples have been investigated by broadband dielectric spectroscopy in a wide range of temperature (40°C-110°C) and frequency (0.1 Hz to 10 MHz). The modulus plots (M′′, M′) illustrate the presence of non-Debye type of relaxations attributed to the effects of interfacial and dipolar polarizations. The real and the imaginary parts of the impedance are well fitted to equivalent circuit models. At high temperatures, Z″max varies from 0.03 × 106 to 4.9 × 106 Ω when the TiO2 doping concentration increases from 1 to 7 wt%. From the obtained results, the secondary phase ZnTiO3 plays an important role in the electrical properties. [ABSTRACT FROM AUTHOR]

Highlights: [•] The effects of different Sn2O3 doping concentrations were investigated. [•] Band gap broadens if the doping concentration increases. [•] The increase in Sn2O3 content, superior or equal to 10wt%, the dielectric loss disappears. [•] The dc conductivity increases with the increase of Sn2O3 doping concentrations. [•] The temperature dependent ac conductivity follows the universal power law. [ABSTRACT FROM AUTHOR]