Deposition of superlattice PbTiO_3/(Pb, La)TiO_3

摘要

Superlattices of perovskite materials are now considered as new approach for the creation of novel ferroelectric properties. The structure of Superlattices is made by a multi-source deposition. In this experiment, PbTiO_3/(Pb, La)TiO_3 (PT/PLT) superlattices were epitaxially grown on (100) MgO by rf-magnetron sputtering. The sputtering apparatus comprises muti-target system. Two powder targets of FT and PLT(20) with an excess of PbO powder (10 mol%) were used for the sputtering. The superlattices were sputtered from the two targets by turns. The modulation wavelength A of the superlattice is controlled by the deposition times of each target. The modulation wavelength was 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 with the satellite signals indicating the formation of the superlattice. The microstructure of the superlattice was studied by a high angle annular dark field- scanning transmission electron microscopy (HAADF- STEM).