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 La2Ti2O7 (LTO) with the substitution of La3+ ions by Ce3+ ions at A sites is designed and synthesized using the conventional solid-state sintering technology. The effects of dopant Ce3+ ions on the microstructure, phase structure, and electrical properties of LTO are investigated methodically. Moderate dopant Ce3+ ions decrease the concentration of thermions in LTO ceramics, but excess dopant Ce3+ ions can lead to cell distortions, which have some relationships with defects. Through analysis, the La1.95Ce0.05Ti2O7 (LCTO-0.05) ceramics with a pure monoclinic phase possess optimal electrical properties. At 650 degrees C, the enhanced fitted direct current (DC) resistivity of the LCTO-0.05 ceramics is 1.5 x 10(6) omega 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.