GROWTH OF CUCL SINGLE-CRYSTALS BY THE TOP SEEDED SOLUTION GROWTH METHOD

CuCl crystals were grown from a solution containing KCl as a flux using the top seeded solution growth method. The essential driving force for growth in this study was mass transport via the temperature gradient and the melt temperatures were kept constant during growth. This is an important distinction from the more common type of top seeded solution growth, where decreasing temperature drives the growth. The effects of the seed orientation ([100], [111] and [110]), KCl concentration (3.0-24.9 mol%) and growth rate (0.25-5.22 mm/h) upon the crystal quality were studied. The most favorable conditions were 3.0 mol% KCl and R approximately-equal-to 0.6 mm/h. Transparent crystals with large grain size (5-10 mm in diameter) were obtained under these conditions. The distribution of KCl inclusions and the internal strains in the crystals were also examined, using the dark-field illumination and the photo-elastic method, respectively.