Crystal Research and Technology
Cryst. Res. Technol. 40, 517 (2005) - Abstract -

Synchrotron X-ray investigation of La0.3Sr0.7Al0.65Ta0.35O3 crystals

W. Wierzchowski, K. Wieteska*, W. Graeff**, H. Sakowska, T. Lukasiewicz, and M. Pawlowska

Institute of Electronic Materials Technology, Wólczyńska 133, 01-919 Warsaw, Poland
*Institute of Atomic Energy, 05-400 Otwock-Swierk, Poland
**HASYLAB at DESY, Notkestr. 85, 22603 Hamburg, Germany

Keywords LSAT, X-ray diffraction, defects
PACS 61.72.Ff
DOI 10.1002/crat.200410377

The La0.3Sr0.7Al0.65Ta0.35O3 (LSAT) substrates were studied with a number of X-ray diffraction methods exploring both synchrotron white and monochromatic beam. The observation of selective etching patterns was performed in neighbouring samples. White beam back-reflection projection topographs revealed only the segregation fringes around the central core and a delicate grain-like structure. The most important for verification of dislocation presence were the transmission projection and section topographs. These topographs also did not reveal any images of extended dislocation but only the growth bands and tiny grain-like structure. The section topographs provided some details of paroboloidal growth surface inside the crystal. It may be concluded that the investigated crystal probably contains small coherent inclusions responsible for the etch pits and the mentioned grain-like structure. The synchrotron rocking curves revealed a number of maxima, which might be attributed to the regions with different lattice parameter, connected with segregation fringes. The sequence of maxima was different for different regions of the sample.




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