  Lead iron niobate (PbFe0.5Nb0.5O3 - PFN) thin films were synthesized by a
modified sol-gel route, which offers the advantage of a rapid, simple and
non-toxic reaction method. Polycrystalline perovskite-structured PFN thin films
without pyrochlore phases were obtained on Pt/Ti/SiO2/Si substrates after
sintering by rapid thermal annealing at 650 {\deg}C. TEM and AFM images
confirmed the excellent quality of the sintered film, while EDS spectroscopy
revealed the presence of oxygen vacancies near the film/substrate interface.
Electric measurements show good dielectric properties and ferroelectric
behavior, characterized by typical C-V curves and well-defined P-E
ferroelectric loops at 1 kHz, with remanent polarization values of ~12 uC/cm2.
The polarization, however, increases with decreasing frequency, indicating the
presence of leakage currents. I-V measurements show a significant increase in
DC-conduction at relatively low fields (around 100 kV/cm). The films display
ferromagnetic behavior at room temperature, with magnetic remanence around 30
emu/cm3 and a coercive field of 1 kOe. These values are significantly higher
than those obtained for PFN powders fabricated by the same sol-gel route, as
well as the magnetization values reported in the literature for epitaxial
films.
