Integration of BiFeO3 thick films onto ceramic and metal substrates by screen printing

This study presents the preparation of bismuth ferrite (BiFeO3) thick films by a screen-printing method. We explain the influence of the annealing temperature on the diffusion processes, occurring through individual layers of the thick-film structure, densification, and interface reactions between ∼15-μm-thick BiFeO3 films and an Al2O3 substrate. The key parameters were identified and include the optimal annealing temperature and substrate purity, which need to be controlled in order to obtain high quality BiFeO3 thick films in terms of phase composition and microstructure. Taking into account these processing parameters, we present compositionally improved and high density BiFeO3 thick films on Ag metal foil, which were sintered at temperatures as low as 740 °C. While the local ferroelectric behavior of the BiFeO3 film has been confirmed by piezo-response force microscopy analysis, its macroscopic electrical response is characterized by a high electrical conductivity coupled with an interface-related diode-like current-voltage behavior.