X-RAY-SCATTERING INVESTIGATION OF A SRTIO3(103) BICRYSTAL INTERFACE

Synchrotron X-ray scattering has been employed to study the structure of a SrTiO3(103) bicrystal interface. The upper part of the bicrystal was thinned down to 25 mu m in order to allow the X-ray beam to penetr ate down to the interface. The X-ray energy was set to 15.7 keV, just below the Sr K edge, to minimize absorption and further to enhance the penetration. No superstructures were detected along the tilt directio n but, surprisingly, satellites were seen in the [010] direction perpe ndicular to the tilt direction in the neighbourhood of the (002) and ( 004) Bragg reflections. The spacing between the satellites was 0.02 re ciprocal lattice units, which corresponds to a spacing of 195 Angstrom along the interface. The satellites were sharp with a width correspon ding to a correlation length in excess of 2600 Angstrom. It is propose d that the satellites originate from sinusoidal modulations at the int erface which arise from a 0.38 degrees misalignment between the crysta ls and propagate from the interface deep into the bulk.