Strontium doped CaCu3Ti4O12 ceramics with very low dielectric loss synthesized by the sol–gel method

The Ca site of CaCu 3 Ti 4 O 12 (CCTO) ceramics doped by strontium (Ca 1- x Sr x Cu 3 Ti 4 O 12 , x = 0.0, 0.1, 0.2, 0.3) were accomplished by a modified sol–gel method and subsequently sintered at 980–1020 °C to improve the dielectric properties and enhance the breakdown electric field. Remarkably, the dielectric loss (tan δ ) of the CSCTO ceramics sintered at 1000 °C can be lower than 0.05 in a wide frequency (20 Hz–100 kHz), especially, very low dielectric loss (tan δ ) about 0.008 can be obtained in Ca 0.9 Sr 0.1 Cu 3 Ti 4 O 12 ceramic which sintered at 1000 °C measured at 300 Hz. These results indicate that Sr 2+ doped at the Ca 2+ site of CCTO type ceramic can enhance the applicable properties of CaCu 3 Ti 4 O 12 and can be used in the future practical researches.