United States of America As Represented by the Secretary of the Air Force

Alton F Armington

Meckie T Harris

John J Larkin

William M Higgins

David F Bliss

John K Kennedy

J Emery Cormier

George G Bryant

New single crystals of ZnGeP.sub.2 are grown by a chemical vapor transport process from bulk synthesized polycrystalline ZnGeP.sub.2 using the LEK process with a controlled injection of phosphorus. The synthesis of the bulk is based on direct injection of phosphorus through a B.sub.2 O.sub.3 encapsulant and reaction with the zinc germanium melt, resulting in synthesis of a large melt (350 g) of ZnGeP.sub.2. When crystallization is followed by cooling the congruent melt down through the .alpha.-.beta. transition temperature (952.degree. C.) as is typical for bulk growth processes, the result is the growth of partially disordered material. This material is placed in a two zone heated furnace where iodine is used to transport the intermediate product to the growth zone where the single crystals grow, at a temperature below the .alpha.-.beta. phase transition. The resulting crystals produced contained a second cubic phase, which has not been reported previously.

Synthesis and growth processes for zinc germanium diphosphide single

The growth of bismuth silicate crystals occurs in a high pressure vessel or autoclave using a hydrothermal growth process. The nutrient material is placed in a sealed container of noble metal, liner, along with a solvent to a selected fill level. A filler fluid is also placed between the liner and the pressure vessel. The oriented seeds are placed in the cooler top seed zone over a baffle that slows the movement of supersaturated liquid from the hotter lower nutrient zone. Using a selected heating schedule for the top and the bottom zones, a plurality of large crystals are grown in the seed zone. The temperature differential is about 5.degree. C.

Hydrothermal growth on non-linear optical crystals

A composite susceptor for a radio frequency (RF) heated crystal growing furnace has a plurality of stacked electrically insulating and electrically conducting elements about the crucible area so that a proper temperature gradient is established and controlled.

Apparatus and method for controlling gradients in radio frequency heating

Ultra high pure quartz is grown by a one step in-situ growth process where the nutrient is high purity silica. A negative temperature gradient is maintained between the nutrient zone and the seed zone until about the start of crystal growth. A sealable container made of silver contains the nutrient and the seed within the autoclave chamber.

Process of making high quality single quartz crystal using silica glass

This invention concerns itself with a method for producing single crystal, seed material for use in growing synthetic quartz crystals. This seed material comprises a Z-faced seed crystal cut or sliced from the X-plus growing region of a synthetic quartz, single crystal boule.

Growing community of inventors

Lexington, MA, United States of America

Alton F Armington