Pb(Zr_(0.52)Ti_(0.48))O_3/TiNi multilayered heterostructures on Si substrates for smart systems

摘要

Ferroelectric/shape memory alloy thin film multilayered heterostructures possess both sensing and actuating functions and are considered to be smart. In this article, Pb(Zr_(0.52)Ti_(0.48))O_3 (PZT) ferroelectric thin films and Ti-riched TiNi shape memory alloy thin films have been deposited on Si and SiO_2/Si substrates in the 400-600℃ temperature range by pulsed laser deposition technique. Deposition processing, microstructure and surface morphology of these films are described. The TiNi films deposited at 500℃ had an austenitic B2 structure with preferred (110) orientation. The surfaces of the films were very smooth with the root-mean-square roughness on a unit cell level. The structure of the TiNi films had a significant influence on that of the subsequently deposited PZT films. The single B2 austenite phase of the TiNi favored the growth of perovskite PZT firms. The PZT/TiNi heterostructures with the PZT and TiNi films respectively deposited at 600 and 500℃ exhibited a polarization-electric field hysteresis behavior with a leakage current of about 2 x 10~(-6) A/cm~2.