Dielectric response and alternating current conductivity in (Co,Ni)Al2O4 nano-spinel

The dielectric behavior and alternating current conduction mechanism of nanocrystalline (Co,Ni)Al 2 O 4 aluminate spinel have been investigated over a broad frequency range (1 kHz to 1 MHz) for different temperatures i.e. 50 °C to 90 °C. The low cost and environmental friendly method has been used to developed the nanocrystalline (Co,Ni)Al 2 O 4 spinel phase. The formation of homogeneous single phase of nanocrystalline (Co,Ni)Al 2 O 4 spinel has been confirmed by X-ray diffraction, transmission electron microscopy and scanning electron microscopy. The dielectric response and alternating current conductivity have been observed by inductance, capacitance and resistance bridge which confirms traditional dielectric behavior of (Co,Ni)Al 2 O 4 . The frequency dependent complex dielectric impedance behavior has also been explored. The activation energy of (Co,Ni)Al 2 O 4 has been found nearly 0.3–0.1 eV b/w the frequency range 1 kHz to 1 MHz. The alternating current conduction mechanism reveals the signature of correlated barrier hopping by following the power law where the maximum barrier length has been found 144 ± 0.25 MeV. This alternating current conduction also follows the Meyer-Neldel rule in the low frequency region.