IONIC DISTRIBUTION AND MICROWAVE DIELECTRIC PROPERTIES FORTUNGSTENBRONZE-TYPE LIKE Ba6-3x R8+2xTi18O54 (R =Sm,Nd and La )SOLIDSOLUTIONS

摘要

Ba6-3xR8+2xTi18O54( R = Sm, Nd and La ) solid solutions have been applied to microwaveresonators and filters for mobile phone because of their high dielectric constant ^ high qualityfactor Q·f and near zero temperature coefficient of resonant frequency rf. In this paper,relationships between cation distribution and microwave dielectric properties in this compoundare presented in four following cases: case 1 is the improvement of quality factor bycompositional ordering; case 2 does more compositional ordering result in higher quality factors;case 3 the quality factor dependence on R-cations; and case 4 the correlation of trigonal siteoccupation with microwave dielectric properties.