High-frequency transport properties of spin-spray plated Ni-Zn ferrite thin films

The frequency and temperature variation of magnetoimpedance in Ni-Zn ferrite thin films fabricated by spray plating method were studied. It is observed that the frequency induces a metal-insulator crossover behavior in impedance spectra. The frequency behavior of the electrical properties of the film can be modeled by an equivalent circuit composed of resistance and capacitance. The relaxation time and activation energy of the conductivity were calculated. The result suggests that the high-frequency conductivity of the spin-spray plating of a Ni-Zn ferrite film is predominantly associated with the dielectric, rather than by magnetization, dynamics. Mechanisms underlying high-frequency transport are discussed. (C) 2003 American Institute of Physics.