| Article ID | Journal | Published Year | Pages | File Type |
|---|---|---|---|---|
| 728261 | Materials Science in Semiconductor Processing | 2015 | 7 Pages |
A new perovskite ceramic material with the composition La2/3CuTa4O12 was synthesized by solid state reaction method. SEM observations revealed dense and fine-grained microstructure and not uniform grain size distribution in the ceramics sintered in the temperature range 1180–1220 °C. Impedance spectroscopy studies were carried out in the temperature range from −55 to 700 °C at frequencies 10 Hz–2 MHz. Three types of dielectric responses were recognized, attributed to grains, grain boundaries and the electrode-sample interface. The relaxation times determined from the impedance data follow the Arrhenius law with the activation energies of 0.25 eV and 0.94 eV for grains and grain boundaries, respectively. DC electrical conductivity of the investigated ceramics was investigated in the temperature range 20–700 °C. The determined activation energy of electrical conduction was about 0.5 eV. The dielectric properties of La2/3CuTa4O12 ceramics were compared with those of other A2/3CuTa4O12 (A=Y, Nd, Sm, Gd, Dy, Bi) materials, being the spontaneously formed internal barrier layer capacitors, and some essential differences were found.
