Crystal structure and electrical properties of epitaxial SrBi2Ta2O9 films

The crystal structure and electrical properties were investigated for (001)- and (116)-oriented SrBi2Ta2O9 (SBT) thin films deposited on (100) SrTiO3 and (100)SrRuO(3)parallel to(100)SrTiO3 substrates, and (110) SrTiO3 and (110)SrRuO(3)parallel to(110)SrTiO3 substrates, respectively. Both oriented SBT films were epitaxially grown with high crystal perfection, and twinning existed in the (116)-oriented one. Both oriented SBT films were found to form c/6 lattice displacements to relax the stress. The interface of the (001)-oriented film did not include misfit dislocations, defects, and an interfacial layer, and that of the (116)-oriented film included the lattice strain contrast due to an irregular atomic arrangement. The electrical property of the SBT film shows anisotropy of the ferroelectricity along the c- and a-axis directions; the remanent polarizations of the (001)- and (116)-oriented SBT films were 0 and 10.5 mu C/cm(2), respectively. (C) 2000 American Institute of Physics. [S0021-8979(00)02111-3].