Journal of the American Ceramic Society · 1947 · 90 citations · 0 references
Natural SciencesMaterials EngineeringMaterials ScienceCeramic MaterialsInorganic ChemistrySolid State PhysicsDielectric CeramicsDielectricsElectrical Properties Of CeramicsPerovskite MaterialsThermal Properties Of CeramicsThermal Properties Of MaterialsBarium TitanateDielectric ConstantDielectric Constant MeasurementLinear Thermal ExpansionPower FactorStrontium Barium TitanateThermal ExpansionThermal Expansion In Ceramics
A bstract The results on barium‐strontium titanates are given for heat‐treatment, absorption, shrinkage, thermal expansion, dielectric constant, K , at minus 60° to 85°C. and also for Q (the reciprocal of the power factor) at 25°C. for frequencies of 50 kc. per sec. to 20 mc. per sec. A few measurements of K and Q were made at 3000 mc. per sec. Specimens with an absorption of less than 0.l% matured at 1250° to 1430°C. K values ranged from 34 for BaO:4TiO 2 to several thousand for specimens with compositions on the BaTiO 3 ‐SrTiO 3 join. The BaO: 5TiO 2 specimens were unique in that their temperature coefficient of K was practically zero. O values ranged from 50 to 100 for test pieces containing more than 40% of BaO and from 400 to 10,000 for those with less than 40% of BaO. K values did not change appreciably with frequency. Linear thermal expansions (between 25° and 700°C.) ranged from 0.6 to 0.84%. Many of these specimens could be used in radio equipment.