Influência da ferrita de cobalto (CoFe2O4) na formação da fase β em compósitos magnetoelétricos à base de Poli(Fluoreto de Vinilideno) (PVDF)

Abstract

This work presents a study of the influence of Cobalt Ferrite (CoFe2O4) in the formation of β phase in composite magneto electric the based poly vinylidene fluoride (PVDF), varying the drying time and solvent removaltemperature. The cobalt ferrite used in this work presents the iron in the +3 oxidation state and cobalt in the +2 oxidation state , and has inverted spinel structure. The PVDF films doped Cobalt Ferrite (CoFe2O4) were prepared by the method of crystallization from the solution of PVDF in DMF in concentrations of 10 and 20% (mm-1) of ferrite with PVDF. The characterizations were performed by infrared spectroscopy, X-ray diffraction, scanning electron microscopy and optical microscopy. It was therefore estimated the relative percentage of β phase and identifying the incorporation of dopants in the polymer matrix. The experimental results show that the PVDF matrix doped cobalt ferrite there is an increase in the percentage of phase β as a function of the concentration of ferrite. It was also found that the action of a constant magnetic field creating a mechanical anisotropy due to interaction with the Cobalt Ferrite not significantly influence the formation of the phases of the polymer matrix . The results obtained in this study, it is concluded that the process of doping with Cobalt Ferrite in PVDF is an effective way of increasing the concentration of β phase of the polymer, as is the desired phase due to technological applications such as sensors and electronic actuators.