Dendritic seed crystals having a critical spacing between three interior twin planes

摘要

PICT:0913678/III/1 In pulling a dendritic crystal upwards from a supercooled melt using a seed crystal having three interior twin planes and orientated as shown in Fig. 2, the outer planes are spaced from the inner plane respective distances (A and B) of 0,5-5 and 0,5-30 microns. Preferred distances are 1,7 and 5 microns. One or two dendritic crystals grow from a single seed depending on the conditions of pulling. A pulled dendritic crystal may have a thickness of 1-25 mils and a width of 20-200 mils. Further details of crystal materials and conditions of pulling are as in Specifications 889,058 and 913,674.