Domain structure and surface morphology of epitaxial PbTiO3/SrRuO3 heterostructures on vicinal (001) SrTiO3 substrates

Epitaxial ferroelectric PbTiO3/SrRuO3 heterostructures have been grown on ( 001) SrTiO3 substrates with 1.7 and 5 degrees miscut toward [010] by rf mag netron sputtering. X-ray diffraction indicates that heterostructures with t hin PbTiO3 layer (120, 400, and 1250 Angstrom) consist of purely c-axis PbT iO3 domain, while the thicker PbTiO3 layer (2500 Angstrom) contains both a- asis and c-axis PbTiO3 domains. The bottom SrRuO3 layer is single domain wi th [110] normal orientation. Furthermore, both PbTiO3 and SrRuO3 layers are of very good crystalline quality from the measurements of the full width a t half maximum of rocking curve and in-plane phi scans. Atomic force micros copy studies show that both SrRuO3 and PbTiO3 layers are grown by step flow mechanism, which results in very smooth surfaces (the root mean square rou ghness approximate to 12 Angstrom for a 400 Angstrom PbTiO3/SrRuO3 heterost ructure on a 1.7 degrees miscut substrate over a 2 x 2 mu m area). Our resu lts demonstrate that the high quality epitaxial ferroelectric PbTiO3 hetero structures can be prepared by using SrRuO3 bottom electrodes on miscut (001 ) SrTiO3 substrates for ferroelectric device applications. (C) 1998 Elsevie r Science S.A. All rights reserved.