Ferroelectric Relaxor Thin Films Grown by Pulsed Laser Deposition

Relaxor ferroelectric thin films have been deposited by PLD on Si, MgO and Sapphire substrates. For the deposition, sintered targets of PMN-PT and PLZT with variable contents of PT and La respectively have been prepared by mixed oxide method. The films have been deposited on different substrate-bottom electrode configurations, under different conditions. Films composition and crystallinity were studied by SIMS and XRD techniques. The complex dielectric permittivity was measured at different frequencies and temperatures. Ferroelectric hysteresis measurements were performed at different temperatures. UV laser ablation and substrate temperatures higher than 600 °C have allowed to obtain crystalline PMN-PT and PLZT films. A columnar structure was evidenced by cross-section TEM. The degree of crystallinity, stoichiometry and orientation as well as the relative dielectric constant of the obtained films have been correlated with the deposition parameters.