Very large dielectric constant of highly oriented Pb_(1-x)Ba_xTiO_3 thin films prepared by chemical deposition

摘要

Highly (100) oriented Pb_(0.8)Ba_(0.2)TiO_3/LaNiO_3 structures were grown on LaAlO_3(100) substrates by using a wet, soft chemical method and crystallized by the microwave oven technique. The Au/PBT/LaNiO_3/LaAlO_3 capacitor shows a hysteresis loop with remnant polarization, P_r, of 15 μC/cm~2, and coercive field, E_c, of 47 kV/cm at an applied voltage of 3 V, along with a dielectric constant over 1800. Atomic force microscopy showed that Pb_(0.8)Ba_(0.2)TiO_3 is composed of large grains about 300 nm. The experimental results demonstrated that the microwave preparation is rapid, clean, and energy efficient. Therefore, we demonstrated that the combination of the soft chemical method with the microwave process is a promising technique to grow highly oriented thin films with excellent dielectric and ferroelectric properties, which can be used in various integrated device applications.