Electrical Properties of La2−xCexTi2O7 (x = 0–0.1) Ceramics

As an important functional material, the applications of piezoelectric materials have shifted from convenient use to service in extreme environments. Herein, a new layered high‐temperature ceramic La 2 Ti 2 O 7 (LTO) with the substitution of La 3+ ions by Ce 3+ ions at A sites is designed and synthesized using the conventional solid‐state sintering technology. The effects of dopant Ce 3+ ions on the microstructure, phase structure, and electrical properties of LTO are investigated methodically. Moderate dopant Ce 3+ ions decrease the concentration of thermions in LTO ceramics, but excess dopant Ce 3+ ions can lead to cell distortions, which have some relationships with defects. Through analysis, the La 1.95 Ce 0.05 Ti 2 O 7 (LCTO‐0.05) ceramics with a pure monoclinic phase possess optimal electrical properties. At 650 °C, the enhanced fitted direct current (DC) resistivity of the LCTO‐0.05 ceramics is 1.5 × 10 6 Ω cm. The activation energy of conductivity and relaxation activation energy of imaginary impedance Z″ for LCTO‐0.05 ceramics are 1.12 and 1.16 eV, respectively, in the high‐temperature regime. The piezoelectric coefficient d 33 of LCTO‐0.05 ceramics is up to 3.6 pCN −1 . It is believed that this ceramic system promotes the development of LTO‐based high‐temperature piezoelectric ceramics.