Abstract
Undoped and Mg-doped barium strontium titanate (BST) thick films with thickness of 10-50 μm have been fabricated on alumina substrates using a screen-printing method. Dielectric and microwave properties of the films have been characterised over the temperature range -70 to 70°C. The low frequency (<1 MHz) and high frequency (1-2 GHz) properties have been measured using an impedance analyser and a split post method respectively. The results show that the porous BST films possess permittivity of 100-500 and tunability of 5 to 35% at a DC bias field <2 kV/mm. It seems that Mg-doping and the use of lower sintering temperatures dramatically decrease the temperature dependence of the dielectric properties. Films derived from mixed-oxide powders generally exhibit higher tunability than those from titanate powders even though their grain sizes are similar. However, the dielectric losses of the films have been measured to be in the range 10-2 to 10-1, and are generally one order of magnitude higher than their bulk ceramic counterparts (10-3 to 10-2). The relationships between the composition, microstructure and dielectric properties of the films and the film/substrate interface are discussed. (5 pages)
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
