Ferroelectric behaviors and charge carriers in Nd-doped Bi4Ti3O12 thin films -: art. no. 034101

Nd-doped Bi4Ti3O12 thin films, (Bi3.25Nd0.85)(4)Ti3O12, of layered perovskite structure were synthesized by rf sputtering, followed by postannealing at 600 - 700 degreesC. They show enhanced ferroelectricity with rising postannealing temperature in the range of 650 - 750 degreesC. When annealed at 700 degreesC, a remanent polarization 2P(r) of 25.2 muC/cm(2) and a coercive field E-c of 87.2 kV/cm were measured at 9 V, together with an almost fatigue-free behavior up to 1.4 x 10(10) switching cycles. Their ferroelectric, dielectric, and ac conductivity properties over the temperature range from 25 to 300 degreesC were studied over the frequency range of 0.1 - 1 MHz. Space-charge relaxation by oxygen vacancies was shown to play an important role in determining the dielectric and conductivity behaviors of Nd-doped Bi4Ti3O12 thin films. (C) 2005 American Institute of Physics.