The effect of sputtering atmosphere parameters on dielectric properties of the ferromagnetic alloy – ferroelectric ceramics nanocomposite (FeCoZr)x(PbZrTiO3)(100−x)

Abstract

Two samples of the ferromagnetic alloy – ferroelectric ceramics nanocomposite (FeCoZr)x(PbZrTiO3)(100−x) of similar metallic phase contents have been produced using ion-beam sputtering in the atmosphere of argon and oxygen. The samples have been produced in order to examine the influence of sputtering atmosphere parameters on electrical properties of the tested materials.In a nanocomposite of a reduced oxygen content, a conductivity increase by about three orders occurs along with the increasing frequency, which is associated with the occurrence of hopping recharging. Over the whole area of low measuring frequencies, negative values of the phase shift and a capacitive type of conductivity occur. For the frequency of about 106Hz, the phase shift reaches zero, which corresponds to the voltage resonance phenomenon. For higher frequencies, positive phase shift values and inductive conductivity occur. For a sample of a higher oxygen content, phenomena of voltage resonance (low frequency values) and current resonance (high frequency values) can be observed. When the oxygen content increases, frequency dependences of the phase difference get shifted into the low frequency area. This is associated with the surface oxidation or a complete oxidation of the metallic-phase nanograins, which increases the potential barrier as well as with an increase of the relaxation time activation energy. For the sample of a higher oxygen content, an increase of the conductivity activation energy has been observed in the low temperature area.