BaTiO 3 Film Grown by Water-Based Process

Self-assembled nano-crystalline BaTiO 3 films on stainless steel foil substrates, were grown by the water based Streaming Process for Electrodeless Electrochemical Deposition (SPEED). SPEED is an aqueous process that deposits self-assembled nano-crystalline inorganic thin films over large areas, without a vacuum, providing a scalable and manufacturing friendly process to fabricate durable films. The morphology of the ~1 µm thick films comprises single crystals of micron dimensions imbedded in a matrix of nanocrystals. XRD confirms presence of BaTiO 3 crystals of hexagonal phase for samples annealed at 500 C. Subsequent annealing at 600 C transforms the film to the cubic phase. Potential applications include dielectric layers, capacitors, waveguides, ferroelectric RAM, pyroelectric infrared detectors, and phosphors. Characterization of infrared pyroelectric response at 10 µm wavelength shows an initially good sensitivity that reversibly decays over a period of days due to water vapor absorption. A short-lived photo-response due to poling of the hydrated sample is also observed.