Journal of Applied Physics · 2005 · 115 citations · 12 references
Natural SciencesMaterials EngineeringMaterials ScienceCeramic MaterialsCeramicsMaterials CharacterizationCeramic CompositesDielectric CeramicsDielectric MaterialsDielectric PropertiesDielectricsElectrical Properties Of CeramicsBarium TitanateBarium Titanate CeramicsCeramic DielectricsComposite CeramicsComposite DielectricsDielectric ConstantPhase Transition TemperatureSoft-mode Theory
The dielectric properties of BSTO∕Mg2SiO4∕MgO composite ceramics have been investigated systematically. The dielectric properties of BSTO composites under a dc bias field can be interpreted by the “soft-mode” theory near the phase transition and Johnson’s phenomenological equation far above the transition temperature. Compared with most of the other BSTO composite ceramics, BSTO∕Mg2SiO4∕MgO not only can be sintered at a lower temperature but also keep a higher dielectric tunability versus a lower dielectric constant. For example, BSTO∕35wt.%Mg2SiO4∕15wt.%MgO has a dielectric tunability ∼13.18% (under 2kV∕mm biasing) versus a dielectric constant εr(0)∼118.40 at 25°C. It suggests that the dielectric properties are influenced to a great extent by the microstructure, and the dielectric tunability is enhanced when more continuous BSTO phase is obtained.
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Structural phase transitions I. Landau theory
R. A. Cowley · Advances In Physics · 1980 · 482 citations