Microstructural and Electrical Characterization of W Substituted Barium Strontium Titanate Ferroelectric Ceramics (original) (raw)

Ferroelectrics are multicomponent materials with a wealth of interesting and useful properties, such as piezoelectricity. The dielectric constant of the BSTO ferroelectrics can be changed by applying an electric field. Variable dielectric constant results in a change in phase velocity in the device allowing it to be tuned in real time for a particular application. The microstructure of the film influences the electronic properties which in turn influences the performance of the film. Ba0. 6 Sr0. 4 Ti 1-y(A 3 +, B'÷),O 3 thin films, of nominal thickness of 0.65 gim, were synthesized initially at substrate temperatures of 400'C, and subsequently annealed to 750'C, on LaAIO 3 (100) substrates, previously coated with LaSrCoO conductive buffer layer, using the pulsed laser deposition technique. The microstructural and physical characteristics of the postannealed thin films have been studied using x-ray diffraction, scanning electron microscopy, and nano indentation and are reported. Results of capacitance measurements are used to obtain dielectric constant and tunability in the paraelectric (T>T,) regime.