Thickness-Dependence of Asterism at Transmission Laue Method

Abstract

At the transmission Laue Method，the asterism of diffracted beam varies according to the thickness of crystal specimen. The diffraction patterns were obtained when pure aluminium plates deformed were successively decreased in thickness by electropolishing. It has been known that the asterism magnitude of the diffracted beam varies proportionally to the thickness less than 0.2 mm and is saturated for the thickness larger than 0.3 mm. The former fits well with a simple estimation of the effect of the thickness on the asterism. For the thin specimen，the proportionality can be explained by a simple curved lattice model of the crystal. If the asterism magnitude of thin crystal is divided by the thickness，this divided value is proportional to the curvature of the lattice and may also be used tothe quantitative measurement of the crystal deformation