Ag-Ba0.75Sr0.25TiO3 composites with excellent dielectric properties

The percolative ceramic composites of Ba0.75Sr0.25TiO3/Ag (BST/Ag) with dense microstructure were sintered at a low temperature of 960 degrees C. Excellent dielectric properties, such as high dielectric constant (epsilon(r)similar to 24 000), low dielectric loss, and high dielectric tunability, were reported. The dielectric constant is found to be nearly temperature and frequency independent. It is essential to introduce the low-melting-point metal of silver into BST ceramics for significantly enhancing the dielectric properties of the composites. The superproperties make it potential to be used for electronic devices such as high charge-storage capacitors and tunable filters. (c) 2008 American Institute of Physics.