CoFe2O4 (CFO) thin films were deposited on (Bi3.25Nd0.65Eu0.10)Ti3O12 (BNEuT) micropillar films by a non-aqueous sol-gel method. The pitch size of 2–5 μm in the micropillar films used as ferroelectric pillars, and 5 and 15 CFO deposition cycles were examined for high density of CFO nanoparticles. All the CFO films formed by five deposition cycles on BNEuT micropillar films with a pitch size of 2–5 μm were composed of mostly single-phase CFO with a cubic inverse-spinel structure. All the CFO films deposited on the four BNEuT micropillar films were highly dense and had excellent surface flatness, based on surface field-emission scanning electron microscope observations. Based on the structural, magnetic and ferroelectric characteristics, the optimal pitch size for achieving a high density of CFO nanoparticles was 5 μm, and the optimal number of CFO deposition cycles was five.
By depositing a high-density ferromagnetic cobalt ferrite (CFO) layer in the rod gaps in c-axis-oriented epitaxial Bi3.9Nd0.3Eu0.1Ti3O12.5 (BNEuT) films with a microrod morphology by metal organic decomposition (MOD), microrod-type multiferroic CFO/BNEuT composite thin films were fabricated. The effects of the soaking time during the annealing treatment on the structural, magnetic, and ferroelectric characteristics of the resulting composite films were investigated. The MOD-deposited and annealed films contained single-phase CFO with a cubic inverse-spinel structure. The Fe/Co ratio for the annealed samples gradually increased with increasing soaking time from 3 to 10 h, because of the transfer of Co atoms from the bottom layer during high-temperature aging. The CFO/BNEuT composite films annealed at 700 °C for 1–10 h exhibited magnetic shape anisotropy, and annealing under a nitrogen atmosphere was effective for improving the magnetic properties. Little soaking time dependence was found for the remanent polarization, which was almost constant at 1.0–1.5 μC cm−2.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.