Piezoelectric Pb0.7La0.2TiO3 prepared by pulsed laser deposition on (100)InP

La-modified PbTiO3 (PLT) thin films have been deposited by pulsed laser dep osition on (100)InP substrates. The nominal target composition was selected to optimize piezoelectric properties of the material. It is shown that PLT deposition on as-received InP produces amorphous PLT films because of the presence of a native oxide on the substrate. PLT films deposited on bare In P have poor adhesion as a result of the surface reoxidation of the substrat e due to the high oxygen pressure required for the deposition of stoichiome tric PLT. To prevent substrate oxidation, several buffer oxides (CeO2, ZrO2 , SrO, Y-stabilized ZrO2, MgO, and SrTiO3) have been grown in vacuum on (10 0)InP. Highest-quality heteroepitaxy was found with Y-stabilized ZrO2 (YSZ) , being [100]{100} YSZ parallel to [100]{100} InP oriented. The PLT deposit ed on this buffer layer is oriented with the [101] direction perpendicular to the substrate surface plane.