DIELECTRIC BEHAVIOUR OF MAGNETIC NICKEL NANOPARTICLES ENCAPSULATED IN SILICA

Abstract

The impedance measurement showed activation energy of 1.3 eV and decrease in dc conductivity with temperature. The high dielectric constant over a wide frequency range is explained as a consequence of concentration of Ni much higher than the percolation threshold. The conductivity mechanism is dominated by tunneling at low frequency and electron hopping at high frequencies. The material suffers a low loss in high frequency range, making it suitable for high frequency magnetic applications.