X-ray diffuse scattering study of defects in α-sapphire

Jerzy Gronkowski ,  Elżbieta Zielińska-Rohozińska ,  Janusz Borowski 

Warsaw University, Institute of Experimental Physics (IEP UW), Hoża 69, Warszawa 00-681, Poland


Sapphire single crystals have been widely studied in the past few decades because this material is used on a large scale as substrate for the epitaxial technique, e.g. in the laser and light emitting diode fabrication. Various dislocations with different Burgers vectors were studied by x-ray topography [1-3]. Theoretical and experimental results of x-ray topographical investigations of perfect dislocations were reported in [4]. In the present study 006 reflection CuKα1 maps from both sides of α-Al2O3 substrate were taken in the triple-axis mode. The obtained isointensity contour shapes revealed features resembling those from dislocation loops in other materials. In order to identify the defects the isocontours were simulated using the double-force tensor approach [5] applied to hexagonal crystals [6, 7].

[1] Y. Takano, K. Kohn, S. Kikuta, K. Kohra, J. Appl. Phys. (1970) 847.

[2] J.L. Caslavsky, C.P. Gazzara, R.M. Middleton, Phil. Mag. 25 (1972) 35.

[3] J.L. Caslavsky, C.P. Gazzara, Phil. Mag. 26 (1972) 961.

[4] C. G'Sell, Y. Epelboin, J. Appl. Crystallogr. 12 (1979) 110.

[5] H. Trinkaus, phys. stat. sol. (b) 51 (1972) 307.

[6] Th. Michelitsch, A. Wunderlin, phys. stat. sol. (b) 198 (1996) 615.

[7] Th. Michelitsch, phys. stat. sol. (b) 203 (1997) 3.


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Presentation: poster at E-MRS Fall Meeting 2005, Symposium F, by Jerzy Gronkowski
See On-line Journal of E-MRS Fall Meeting 2005

Submitted: 2005-06-01 07:30
Revised:   2009-06-07 00:44