Preparation and structure of Ba2Ti9O20 and BaTi4O9 ceramics derived from sol-gel powders

Ba2Ti9O20 (B2T9) and BaTi4O9 (BT4) ceramics have been fabricated using sol-gel technique. The sol-gel derived powder was produced from barium acetate and butyl titanate using acetic acid as solvent. The as-prepared powders were then calcined at different temperatures ranging from 600degrees to 1200degreesC. After that, the powder was pressed into pellets and further sintered at different temperatures ranging from 1250degreesC to 1380degreesC. XRD characterization and Raman spectroscopy showed that after calcining the sol-gel powder at 900degreesC for 2 h and sintering the pressed pellets at 1330degreesC for 4 h, triclinic B2T9 and orthorhombic BT4 ceramics could be obtained. The dielectric constant and Q-value are 35 and 19 10 at 6.1 GHz.