Layered lead zirconate titanate and lanthanum-doped lead zirconate titanate ceramic thin films

Abstract

The physical layering of sol-gel-derived lead zirconate titanate (PZT) 52/48 and lanthanum-doped PZT (PLZT) 2/52/48 on platinized silicon substrates was investigated to determine if the ferroelectric properties and fatigue resistance could be influenced by different layering sequences. Monolithic thin films of PZT and PLZT were characterized to determine their ferroelectric properties. Sandwich structures of Pt/PZT/PLZT/PLZT/PZT/Au and Pt/PLZT/PZT/PZT/PLZT/Au and alternating structures of Pt/PZT/PLZT/PZT/PLZT/Au and Pt/PLZT/PZT/PLZT/PZT/Au were then fabricated and characterized. X-ray photoelectron spectroscopy depth profiles revealed that the layering sequence remained intact up to 700 °C for 45 min. It was found that the end layers in the multilayered films had a significant influence on the resulting hysteresis behavior and fatigue resistance. A direct correlation of ferroelectric properties and fatigue resistance can be made between the data obtained from the sandwiched structures and their end-layer monolithic thin film counterparts. Alternating structures also showed an improvement in the fatigue resistance while the polarization values remained between those for PZT and PLZT thin films.