Controlled growth of a-/b- and c-axis oriented epitaxial SrBi2Ta2O9 ferroelectric thin films

Abstract

Thin films of $\mathrm{a-/b}$ - and c-axis oriented ${\mathrm{SrBi}}_{\mathrm{2}}{\mathrm{Ta}}_{\mathrm{2}}{\mathrm{O}}_{\mathrm{9}}$ (SBT) were epitaxially grown on (110) MgO and (100) MgO substrates, respectively, by a rf magnetron sputtering deposition method. The orthorhombic SBT phase was confirmed by electron probe microanalysis and infrared reflectance spectra. The oriented growth was proved by transmission electron microscopy together with x-ray diffraction. The orientation relationship of the $\mathrm{a-/b}$ -axis oriented film with the substrates was determined to be SBT[001]//MgO[001] and $\mathrm{SBT[010]//MgO[11̄0](SBT[100]//MgO[11̄0])}$ from electron diffraction patterns.