Microstructures, ferromagnetic, and ferroelectric properties in polyvinylpyrrolidone-assisted CoFe2O4/Pb(Zr0.53Ti0.47)O-3 multiferroic composite thick films

摘要

CoFe2O4/Pb(Zr0.53Ti0.47)O-3 (CFO/PZT) multiferroic composite thick films with different CFO mass fractions have been prepared onto Pt/Ti/SiO2/Si substrate by a hybrid sol-gel process and spin coating technique. Polyvinylpyrrolidone (PVP) was employed to be an assistance to the sol-gel solution for enhancing the film thickness and promising a crack-free film surface. After annealing at 650 A degrees C in air for 1 h, phase structure, microstructure, magnetic and ferroelectric properties as well as leakage current of multiferroic thick films were investigated. X-ray diffraction indicated a deeply buried distribution of CFO particles in the PZT matrix. Scanning electronic microscopes showed crack-free surfaces and a decreasing film thickness from 7.2 mu m to 6.2 mu m with increasing CFO content. Furthermore, the saturated magnetization and remanent magnetization were also hence increased. In addition, mass fraction of CFO in PZT matrix was also estimated from 0.36% to 4.58% according to the relationship between M (s) and magnetic content. Ferroelectric hysteresis loops revealed saturated polarization (P (s)) and remanent polarization (P (r)) were diluted by CFO till its mass fraction rising to 1.8%. After that, polarization was increased with further increasing CFO content. Enhanced leakage was demonstrated to be partially contributed to them. A critical content of 1.8% was hence confirmed, where ferroelectric and magnetic properties can be balanced, indicating a possible stress-transferred magnetoelectric coupling effect in this composite.