Structural and electrical properties of BaTi4O9 microwave ceramics incorporated with glass phase

BaTi4O9 (BT4) microwave ceramics incorporated with ZnO-B2O3 glass phase were fabricated by a conventional mixed oxide reaction method. A density of 4400 kg m(-3) was gotten for ceramic sintered at 1200 degreesC for 2 h, very close to the theoretical density of 4533 kg m(-3) of pure BaTi4O9. Shifting of the vibration modes in FTIR and Raman spectra was observed for the ceramics sintered at a higher temperature. Partial melting was also observed in these ceramics. The relative permittivity of the ceramics changed between 45 and 50 as the sintering temperature increased from 1200 to 1400 degreesC. These results indicated that by the incorporation of the glass phase, the sintering temperature of BaTi4O9 ceramics could be reduced to 1200 degreesC while the dielectric ceramics had larger relative permittivities. (C) 2002 Elsevier Science B.V. All rights reserved.