Growth behavior of pulsed-laser-deposited PLZTO thin films

Elemental depth profile examined using secondary ion mass spectroscopy and structural profile examined using grazing-incident X-ray diffractometry were applied to analyze the growth behavior of Pb1-xLax(ZryTi1-y)O-3 (PLZTO) and Pb1-xLaxTiO3 (PLTO) thin films deposited on a Si substrate. When deposited under a suitably high substrate temperature, the chamber's oxygen pressure was observed to substantially influence the structure of the films. Low oxygen pressures (P-O2 < 0.01 mbar) deteriorate crystal structure without altering the composition of the films. Deposition of a buffer layer enhanced the formation kinetics of PLZTO and PLTO films. However sufficiently thick SrTiO3 (similar to 500 nm) layer was required to achieve this effect Using (La0.5Sr0.5)CoO3/Pt materials as double-layer electrodes not only prevented the film-to-substrate interaction, but resulted in preferentially oriented thin films. Ferroelectric properties of the films were thus greatly improved, with remanent polarization (Pr) around 14 similar to 16 mu C/cm(2), coercive force (Ec) around 50 similar to 60 kV/cm, and relative dielectric constant (epsilon(r)) around 900 similar to 1,000.