Fe-Doped LaNiO3 Thin Films as Electrodes for BiFeO3 Ferroelectric Thin Films

The Fe-substituted LaNiO3 (in a formula LaNi1-xFexO3, or LNFO-x in short) thin films were used as electrodes for the BiFeO3 (BFO) ferroelectric thin films. The effect of Fe substitution on the microstructures and the ferroelectric properties of BFO thin films has been investigated. The BFO/LNFO-x thin films were deposited on Si(100) substrates by a chemical solution deposition method. An improved crystallization of LNFO-x was observed as a consequence of Fe incorporation. The resistivity of the conductive LNFO-x thin films changed from 1.68 x 10(-3) Omega.cm to 3.81 x 10(-3) Omega.cm with the increasing Fe content in the investigated composition range (0 <= x <= 0.15). The perovskite-type BFO thin films with random orientations were well crystallized on the LNFO-x electrodes. The remnant polarization and the permittivity of the BFO thin films increased monotonously with Fe content in the LNFO-x electrodes, while the dielectric loss was almost unchanged. The great improvement in the dielectric and ferroelectric properties of the BFO thin films was described to the resisting of Fe diffusion from BFO to the electrodes due to the existence of Fe in the LNFO-x electrodes.