Dielectric properties of low-temperature sintered Ba0.6Sr0.4TiO3 thick films prepared by reactive sintering method

Screen printed Ba0.6Sr0.4TiO3 (BST6/4) thick films were fabricated by reactive sintering at a low temperature below 900 °C. The dielectric properties in radio frequency range were measured on samples of sandwich structure MIM capacitors by impedance analyzer, while that in microwave frequency range were measured on samples of thick films without top and bottom electrodes by split-post dielectric resonator method. The thick films exhibited a low permittivity, while at the same time, maintained a high tunability. The permittivity and dielectric loss at 1 MHz were 228.8 and 0.007, respectively. The corresponding values measured at 9.9 GHz were 82.24 and 0.109, respectively. The tunability was as high as 72.4% (150 kV/cm, 10 kHz). This method provides a simple and effective route to obtain thick films with great potential in applications in Low Temperature Co-fired Ceramic (LTCC) and microwave tunable devices.

► Reaction sintering method is used to fabricate BST thick films at relatively low temperature. ► Dielectric properties of films in microwave frequency range are reported and investigated by split-post dielectric resonator method. ► The thick films exhibit low permittivities and high tunabilities, which shows great potentials in applications for LTCC and microwave tunable devices.