Structure and electrical properties of Bi3.15Nd0.85Ti3O12 ferroelectric thin films

Polycrystalline Bi3.15Nd0.85Ti3O12 (BNdT) ferroelectric thin films were deposited on platinized Si substrates by chemical solution deposition. Dense and uniform BNdT films with pure Bi-layered perovskite structure were achieved by rapid thermal annealing the spin-on films at 700 degreesC for 3 min. Well-saturated hysteresis loops with remanent polarization around 10 muC/cm(2) were obtained on Pt/BNdT/Pt capacitors. Typical values of dielectric constant and loss tangent of BNdT films at 10 kHz were 525 and 0.028, respectively. Curie temperature of BNdT films was determined to be around 450 degreesC from temperature dependent dielectric measurement. Pt/BNdT/Pt capacitors showed excellent fatigue resistance with no polarization reduction up to 10(10) switches. Imprints, shifts of hysteresis loops along voltage axis, were observed along with the loss of retained polarization after heat treatment of poled Pt/BNdT/Pt capacitors. However, data loss due to imprint is negligible for BNdT capacitors. The dc leakage current density of BNdT capacitors is in the order of 10(-7)-10(-6) A/cm(2) below 100 kV/cm. (C) 2004 American Institute of Physics.