Electrical transport properties of nanocrystalline nonstoichiometric nickel ferrite at and above room temperature

The electrical transport properties of chemically prepared nanocrystalline nonstoichiometric nickel ferrite followed by high energy ball milling have been reported. The dc conductivity of the samples shows semiconducting behavior. The adiabatic small polaron model is most suitable for analyzing the dc conductivity at higher temperature, whereas at lower temperature Schnakenberg acoustical one phonon assisted hopping model is suitable. The frequency dependent conductivity has been described by power law σ/(f)∝fs and a maximum has been observed in the temperature behavior of ‘s’. The dielectric properties of the samples have been explained in terms of electric modulus vector. Both dc and ac activation energy have been measured for different samples. The metallic electrode and semiconductor junction formed Schottky diode and the diode parameters have been extracted from the capacitance–voltage characteristics.