Perovskite structure development and electrical properties of PZN based thin films

Pb(Zn_1/3Nb_2/3)O₃ (PZN) is a well known relaxor ferroelectric with excellent dielectric properties for capacitor applications and electromechanical properties for sensor and actuator applications. The perovskite structure stabilization of PZN based ceramics and their respective thin films has limited their applications in these devices. The crystallization behavior and the development of the perovskite structure in PZN with the addition of Pb(Zr_0.47Ti_0.53)O₃ (PZT) thin films were investigated using a metal-organic decomposition technique. When the annealing temperature was higher than 600 °C, the perovskite phase crystallized together with a pyrochlore phase. The fractions of the perovskite structure were kept at approximately 80% if the annealing temperature was higher than 700 °C. Otherwise, a new phase appeared when the annealing temperature was approximately 900 °C. Using a lead oxide upper-layer coating technique, a highly (111) oriented PZN based thin film with ∼96% perovskite was prepared. The electrical properties of this thin film were characterized with the remnant polarization, P_r=25 μC/cm², and the dielectric constant, ε′=712, respectively.