| Popis: |
Dielectric properties of CaCu3Ti4O12 (CCTO) ceramics were studied by doping amount of Zr4+ donor on the basis of doping Y3+ donor. Ca0.97Y0.03Cu3Ti4-xZrxO12 (x=0, 0.005, 0.010, 0.015, CYCTZO) ceramics were prepared by reaction sintering method, and the phase structure, microstructure and dielectric properties of the ceramics were studied. The single phase CCTO was detected in all ceramic samples. SEM images of samples showed a high density and uniform-sized microstructure, and the average grain sizes of the ceramics was reduced with increasing content of Zr4+ donor. Interestingly, the dielectric constant (εr) was increased significantly while the dielectric loss tangent (tanδ) was decreased with the suitable doping amount of Zr4+. CYCTZO ceramics with x=0.010 exhibited a relatively high εr value of 1.02×105 at 1kHz. Meanwhile, the improved grain boundaries response and dielectric properties were closely related to the strengthened grain boundaries resistance (Rgb). The present results indicate that the εr was improved and the tanδ was reduced by doping Zr4+ donors in Ca0.97Y0.03Cu3Ti4O12 (CYCTO) ceramics and explained that the electrical properties were closely related to the electrical heterogeneity of ceramic grains and grain boundaries. |
