X-ray topographic study of growth defects of trans-stilbene crystals grown from solutions

Highlight
• Trans-stilbene crystals grown from solutions investigated by X-ray topography.
• Defects include liquid inclusions, striations, sector boundaries, and dislocations.
• Inclusions are the source of dislocations as well as of plastic glide dislocations.
• Results used for growth of 10-cm scale crystals free of visible defects.

Single crystals of trans-stilbene, C14H12, with properties suitable for high-energy neutron detection were grown from solution in anisole and toluene by the temperature reduction method with growth rates up to 6 mm/day. From these crystals, slices of appropriate orientation and thickness of 2–4 mm were cut and studied by X-ray diffraction topography applying the Lang method using CuKα radiation. The topographs exhibit growth defects such as liquid inclusions, dislocations, striations, and faulty growth-sector boundaries. These defects occur in the same typical arrangements and geometries as is observed in all kinds of crystals grown on habit faces from solution. Besides growth dislocations originating from inclusions and propagating with the growth front, many plastic glide dislocations in the shape of loops or half-loops emitted from inclusions by stress relaxation are observed. The glide system underlying this plasticity is discussed.