Heteroepitaxial growth of PZT thin films on LiF substrate by pulsed laser deposition

Thin films of PbZr0.52Ti0.48O3 (PZT) have been epitaxially grown in situ by pulsed laser deposition on (100)LiF single crystal substrates in view of o ptical applications, expected from the large difference between the refract ive indices of PZT (similar to 2.5) and LiF (1.4). High crystalline quality (001) oriented thin films have been obtained for a deposition temperature ranging in a narrow window (490-510 degrees C), as shown by Xrays diffracti on experiments performed in theta-2 theta, theta-scan and phi-scan modes as well as by reflection high energy electron diffraction (RHEED). As well as the structural characteristics, the refractive index (at 632.8 nm) correla tes strongly with the deposition temperature. Corresponding to the best epi taxial quality, the highest value of the refractive index, similar to 2.3, has been obtained. Although this value is lower than the one of the bulk ma terial, the difference with LiF refractive index is quite enough in order t o expect optical applications. (C) 1999 Elsevier Science S.A. All rights re served.