title: Fine grained Ba(1-x)Sr(x)TiO3 ceramics by spark plasma sintering.
abstract: Fine grained Ba(0.75)Sr(0.25)TiO3 (BST) ceramics were prepared via spark plasma sintering technique. BST nano-powders freshly prepared by a low-temperature direct solution synthesis technique were used as starting materials. X-ray diffraction measurements indicated that the ceramics had a pure perovskite phase and the observation under scanning electron microscope revealed that the ceramic had a grain size in the range of 50 to 300 nm. The dielectric properties of the fine-grained BST ceramics were determined at different temperatures and frequencies. At room temperature, the ceramics exhibited a moderate dielectric constant (3962 +/- 10), a good dielectric tunability (53.84% under a dc bias of 19.72 kV/cm). The highest tunability and figure of merit (FOM) values are 83.27% at 50.2 degrees C and 289.28 at 62.3 degrees C, respectively. These results suggested that the BST ceramics are suitable for use in tunable microwave devices.
authors.affiliation: Departement of Imaging and Applied Physics, Curtin University of Technology, GPO Box U 1987, Perth 6845, WA, Australia.
authors.forename: Huyong
authors.initials: H
authors.lastname: Tian
authors.forename: Wanpin
authors.initials: W
authors.lastname: Chen
authors.forename: C E
authors.initials: CE
authors.lastname: Buckley
authors.forename: H L W
authors.initials: HL
authors.lastname: Chan
mesh_terms: D017609:Barium Compounds / Q000737:chemistry*; D002516:Ceramics / Q000737:chemistry*; D003460:Crystallization / Q000379:methods*; D017097:Electric Impedance; D005740:Gases / Q000737:chemistry; D006358:Hot Temperature; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D017609:Barium Compounds; D005740:Gases; D046911:Macromolecular Substances; C024547:barium titanate(IV); D014025:Titanium