Bulk Crystal Growth of Nonlinear Optical Organic Materials Using Inverted Vertical Gradient Freeze Method

A new process for producing large bulk single crystals of benzil (C6H5COCOC6H5) is reported in this paper. Good quality crystals have been successfully grown using this approach to crystal growth. This method seems to be very promising for other thermally stable NLO organic materials also. The entire contents vycor crucible 1.5 inch in diameter and 2 inch deep was converted to single crystal. Purity of the starting growth material is also an important factor in the final quality of the grown crystals. The entire crystal can be very easily taken out of the crucible by simple maneuvering. Initial characterization of the grown crystals indicated that the crystals are as good as other crystals grown by conventional Bridgman Stockbarger technique.