Hydrothermal synthesis of Ba2Ti9O20 nano-powder for microwave ceramics

Ba2Ti9O20 nano-powders for microwave ceramics were prepared by a hydrothermal synthesis route. Raw materials of Ba(OH)(2).8H(2)O (AR), TiO2 (CP)and de-ionized water were used, and the mixture was stirred in an auto-clave at 130-200 degreesC. Resulted powders with particle size of 10-120 nm were washed, dried and pressed into pellets, which were then sintered at 1200-1300 degreesC. Sintering process was analyzed by TGA and DTA. Microstructures of the powder and sintered ceramics were observed by TEM and SEM. Crystalline phases of the ceramics were identified by X-ray diffraction. Dielectric properties of the samples were also measured, displaying dielectric constant of 25-55 and Qf = 1000-15000 GHz at 10 GHz. (C) 2002 Elsevier Science B.V. All rights reserved