Influence of Substrates on the Crystal Structure of Pulsed Laser Deposited Pb(Mg_1/3Nb_2/3)O₃–29% PbTiO₃ Thin Films

Abstract

Lead magnesium niobate-lead titanate [Pb(Mg 1/3 Nb 2/3 )O 3 (PMN)-PbTiO 3 (PT)] films were synthesized using pulsed laser deposition, and the effect of substrates on the deposition behavior of the PMN-PT film was investigated. Phase evolution of PMN-PT thin films was found to depend significantly on the type of the substrate used during deposition. Though a mixture of pyrochlore and perovskite was observed when films were deposited on a Pt/TiO 2 /SiO 2 /Si substrate, the oxide substrates, such as (Ba 0.5 Sr 0.5 )RuO 3 /Si, SrTiO 3 , and LaAlO 3 , enabled the deposition of pure perovskite. Scanning Auger microprobe, transmission electron microscope, and x-ray diffraction analysis showed that an interfacial layer between the substrates and the oxide film was central to the phase evolution behavior. On the Pt/TiO 2 /SiO 2 /Si substrate, an interfacial layer of lead-platinum (Pb-Pt) played a major role in the formation of the pyrochlore phase. However, on oxide substrates, there was no interfacial layer and interdiffusion of A-site cations was observed between the PMN film and the oxide electrodes.