Dielectric BaTiO3-BBSZ glass ceramic composition with ultra-low sintering temperature

Composites made from BaTiO3 with a high addition of B2O3-Bi2O3-SiO2-ZnO (BBSZ) glass (50-90 wt.%) were sintered at 450 degrees C and 400 degrees C. The shrinkage rates of the compositions as a function of temperature were determined by dilatometer. XRD patterns, Raman spectra and microstructures revealed that an additional phase of Bi24Si2O40 was formed when samples were sintered at 450 degrees C and the glass content exceeded 60 wt.%. Composites with an addition of 70 wt.% of BBSZ had epsilon(r) = 132 and 207 and tan delta = 0.0056 and 0.028 at 100 kHz and 100 MHz, respectively. Notably, at 100 MHz, the additional Bi24Si2O40 phase may be the reason that losses of 80-90 wt.% samples were lower than those of BaTiO3 and BBSZ glass. Realized composites with 70-90 wt.% of BBSZ glass sintered at 450 degrees C exhibited a dense structure, high permittivity and acceptable losses. This makes them suitable for various dielectric applications with ultra-low sintering temperature. (C) 2014 Elsevier Ltd. All rights reserved.