Quality Assessment of Sapphire Wafers for X-Ray Crystal Optics Using White Beam Synchrotron X-Ray Topography

✍ Scribed by Chen, W.M. ;McNally, P.J. ;Shvydko, Yu.V. ;Tuomi, T. ;Lerche, M. ;Danilewsky, A.N. ;Kanatharana, J. ;Lowney, D. ;O'Hare, M. ;Knuuttila, L. ;Riikonen, J. ;Rantam�ki, R.

• Publisher: John Wiley and Sons
• Year: 2001
• Tongue: English
• Weight: 162 KB
• Volume: 186
• Category: Article
• ISSN: 0031-8965
• DOI: 10.1002/1521-396x(200108)186:3<365::aid-pssa365>3.0.co;2-9

✦ Synopsis

The white beam Synchrotron X-Ray Topography (SXRT) technique was used to assess the quality of sapphire wafers grown by the Heat-Exchanger Method (HEM) and the Modified Czochralski Method (MCM). Sapphire is a potential new material for X-ray crystal optics, especially for use as Bragg backscattering mirrors for X-rays and Mo ¨ssbauer radiation. The dislocation distribution, dislocation density and Burgers vector of selected dislocations and stacking faults in the sapphire wafers were studied. A correlation between the sapphire quality and its performance as an X-ray backscattering mirror was established in this paper. The results reveal the high quality of the inspected HEM sapphire wafers and their subsequently improved performance as Bragg backscattering mirrors.