Synthesis and characterization of BaTi1−xSnxO3-0.5 mol%GeO2

► BaTi1−xSnxO3-0.5 mol%GeO2 (x = 0, 0.1, 0.3, 0.5) ceramics were prepared at 1190 °C. ► GeO2 improves crystallization and densification. ► Anomalies are noted for the rhombohedral-orthorhombic transition of BT-0.5Ge. ► For x = 0.3 and 0.5, ε′r exhibit nearly constant variation between 200 and 400 K.