Microstructure and properties of highly elongated (Ba0.5Sr0.5)TiO3 thin films by applied electric field annealing

This study examined the effect of applied electric field annealing on the microstructure and microwave properties of Ba0.5Sr0.5TiO3 (BST) thin films grown on LaAlO3 substrates. The ultraviolet–visible transmission spectra and micro-Raman spectra of these BST thin films revealed the band-gap and lattice vibration to be strongly dependent on annealing with an applied electric field. Based on the structural analyses and microwave properties, the variation in the band-gap, the chemical binding states, and the tunability of the films were attributed to the combined effects of applied electric field annealing in highly elongated BST thin films.

► The impact of post-annealing in electric field on the structure, tunability, and dielectric behavior of rf magnetron sputtering derived (Ba,Sr)TiO3 films has been investigated.
► Post-annealing in the proper electric field can increase the tetragonality, Ti-O bond length, and band gap of the thin film and shift binding energy of the Ti 2p spectra.
► The dielectric constant increases with increasing applied voltage.