Dielectric and Percolative Properties of Ba0.5Sr0.5TiO3–Mg3B2O6 Composite Ceramics
Abstract:A rather complete set of experimental data of the (1−x)Ba0.5Sr0.5TiO3–xMg3B2O6 system were provided, and the dielectric (DE) properties dependences on the volume fraction of Mg3B2O6 phase were extensively investigated. The results showed that below the solution limit of Mg2+, the DE constant and loss tangent were substantially reduced, in comparison with that of pure Ba0.5Sr0.5TiO3. With the increasing volume fractions of Mg3B2O6 inclusion, the DE constant decreased monotonously, nevertheless, the tunability of composites had no significant variations from 21.5% to 18.9% under an applied electric field of 30 kV/cm in a wide range up to 67 vol%, and above the percolation threshold (67 vol%), we observed an obvious drop of the tunabilities of composite system. These results are in accordance with the prediction of the modeled results of ferroelectric–DE composites in a spherical inclusion model.
Document Type: Research Article
Affiliations: Functional Materials Research Laboratory, Tongji University, Shanghai 200092, People's Republic of China
Publication date: 2011-04-01