Deposition of superlattice PbTiO3/(Pb, La)TiO3

Superlattices of perovskite materials are now considered as new approach fo r the creation of novel ferroelectric properties. The structure of superlat tices is made by a multi-source deposition. In this experiment, PbTiO3/(Pb, La)TiO3 (PT/PLT) superlattices were epitaxially grown on (100) MgO by rf-m agnetron sputtering. The sputtering apparatus comprises muti-target system. Two powder targets of PT and PLT(20) with an excess of PbO powder (10 mol% ) were used for the sputtering. The superlattices were sputtered from the t wo targets by turns. The modulation wavelength A of the superlattice is con trolled by the deposition times of each target. The modulation wavelength w as varied from 8 to 240 nm and the total thickness of the superlattice was 240 nm. X-ray diffraction shows the highly oriented (001) and (002) peak wi th the satellite signals indicating the formation of the superlattice. The microstructure of the superlattice was studied by a high angle annular dark fleld-scanning transmission electron microscopy (HAADF-STEM).