Enhancement on effective piezoelectric coefficient of Bi_(3.25)Eu_(0.75)Ti_3O_(12) ferroelectric thin films under moderate annealing temperature

摘要

Bi_(3.25)Eu_(0.75)Ti_3O_(12) (BET) thin films were deposited on Pt/Ti/SiO_2/Si(111) substrates by a metal-organic decomposition method. The effects of annealing temperatures 600-800 ℃ on microstructure, ferroelectric, dielectric and piezoelectric properties of BET thin films were studied in detail. The spontaneous polarization (87.4×10~(-6)C/cm~2 under 300kV/cm), remnant polarization (65.7×10~(-6) C/cm~2 under 300kV/cm), the dielectric constant (992.9 at 100 kHz) and the effective piezoelectric coefficient d_(33) (67.3 pm/V under 260 kV/cm) of BET thin film annealed at 700 ℃ are better than those of the others. The mechanisms concerning the dependence of the enhancement d_(33) are discussed according to the phenomenological equation, and the improved piezoelectric performance could make the BET thin film a promising candidate for piezoelectric thin film devices.