Frequency and temperature dependent electrical properties of ZnO–SnO2 nanocomposites

Abstract Results of the studies on structural, dielectric constant (e′), Impedance (Z) and ac conductivity (σ) of sol–gel grown ZnO–SnO2 nanocomposites have been reported. X–ray diffraction (XRD) measurement reveals dual phase nature of all composites without any unwanted impurity phase. Particle size analyzer was used for establishing the nano scale order of both pure oxides. Various structural aspects of the studied nanocomposites have been discussed and correlated with ac conductivity variations with SnO2 content whereas dielectric response has been understood with the help of cole–cole model. Complex impedance spectroscopy has been understood on the basis of Nyquist plot. Frequency dependent ac conductivity strongly obeys the Jonscher's universal power law and understood on the basis of correlated barrier hopping (CBH) mechanism. Electrical properties are found to depend on temperature and frequency and have been discussed in the context of oxygen vacancies, defects, disorder and structural parameters.