Giant magnetocapacitance effect in nickel zinc ferrite impregnated mesoporous silica

Mesoporous silica with a pore diameter of around 5 nm was synthesized by a solution technique. Nickel zinc ferrite (NZF) phase was grown within these nanochannels. The dielectric permittivity showed dispersion as a function of frequency characteristic of a Maxwell-Wagner capacitor. The nanocomposite exhibited a large magneto-capacitance coefficient of 44% at room temperature at an applied magnetic field of 1.5 T. The dielectric loss of the nanocomposite was fairly low (similar to 0.01). The present strategy of composite synthesis will lead to the preparation of materials having large values of magneto-capacitive coefficients for device applications. (C) 2012 Elsevier B.V. All rights reserved.