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 600° to 1200°C. After that, the powder was pressed into pellets and further sintered at different temperatures ranging from 1250°C to 1380°C. XRD characterization and Raman spectroscopy showed that after calcining the sol-gel powder at 900°C for 2 h and sintering the pressed pellets at 1330°C for 4 h, triclinic B2T9 and orthorhombic BT4 ceramics could be obtained. The dielectric constant and Q-value are 35 and 1910 at 6.1 GHz.