Effect of Sn4+ doping on the dielectric and nonlinear J-E properties of CaCu3Ti4.1O12 ceramics with a slight titanium excess for X9R capacitors

Sn4+ doped CaCu3Ti4.1-xSnxO12 (x = 0.00, 0.05, and 0.10) ceramics were prepared using a one-step polymer pyrolysis method. Variation of Delta epsilon ' < +/- 15% over a temperature range of - 60 to 210 degrees C, very low tan delta similar to 0.009-0.012 and giant-epsilon ' similar to 6685-14,194 at 30 degrees C and 1 kHz were achieved in ceramics with x = 0.05 and 0.10 sintered at 1080 degrees C for 7 h. Furthermore, tan delta values of less than 0.03 and Delta epsilon ' < +/- 10% over wide temperatures range of - 60 to 150 degrees C and - 60 to 200 degrees C were obtained in each of the ceramics. Both ceramics are promising candidate materials for X9R capacitor and X-P capacitor applications. The increase of grain boundary resistance (R-gb) with increasing Sn4+ content in the presence of a TiO2 phase are suggested to play an important role in extending Delta epsilon ' < +/- 15% and tan delta < 0.05 over a wider temperature range.