Percolative multi-susceptible PVDF/NZFO composite films with triply controlled high dielectric and magnetic properties

Abstract

Flexible multi-field susceptible films with remarkable properties and high data storage characteristics are promising in modern electronics. In this work, the percolative Ni₀.₅Zn₀.₅Fe₂O₄ (NZFO)/polyvinylidene fluoride (PVDF) composite films with both high permittivity and significant magnetic properties are prepared by dip coating on ITO/glass substrates. The highest permittivity of 74 is achieved with the NZFO volume ratio close to the percolation threshold, which is 20 times higher than that of pure PVDF. Meanwhile, the dielectric loss is kept below 0.1. The saturation and remanent magnetizations of composite films are 42.04 and 5.70 emu/g and the permeability is ∼3.105, reaching 60%-80% of those in the single phase NZFO. Detailed analysis shows that the high permittivity of the composite film is triply controlled simultaneously by the intrinsic characteristic of the PVDF phase, Kirkpatrick's hybridization model and microcapacitor behavior. It will be of broad interest to control both high dielectric and magnetic properties at the same time of many other flexible and susceptible storage devices.