Dielectric and Microwave Properties of Barium Strontium Titanate (BST) Thick Films on Alumina Substrates

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Authors

Abstract

The dielectric and microwave properties of barium strontium titanate (BST) thick films on alumina substrates have been investigated. The BST films were screen printed and sintered at temperatures below 1300 degreesC. At temperatures below the Curie point the BST films exhibit tunability in the range 15-35% under a DC bias field of 2 kV/mm. The dielectric loss is critically dependent on film thickness with lower losses (<10(-2)) for the thicker films (> 100 mum). A relaxation process appears to take place for the BST films in the MHz to GHz frequency regime. The variation of permittivity with bias field exhibits hysteretic behaviour in both the ferroelectric and paraelectric regions. This is believed to arise due to the non-uniform composition and existence of micro/nanopolar phases in the films. (C) 2003 Elsevier Ltd. All rights reserved.

Details

Original languageEnglish
Pages (from-to)2699-2703
Number of pages5
JournalJournal of the European Ceramic Society
Volume23
Issue number14
Publication statusPublished - 1 Jan 2003

Keywords

  • tunability, hysteresis, dielectric properties, (Ba,Sr)TiO3, microwave, films, relaxation