Abstract: A ballast system for a glove box including a fixed platform on which is mounted an inflatable bag on top of which resides a cover and a weight. The variable gas volume of the inflatable bag communicates with that of the glove box via a valved tube. The weight and gas volume are selected to maintain a relatively constant pressure in the glove box despite variations in the glove box volume while avoiding the use of complicated valving apparatus.

Abstract: A macrocrystalline or single crystal semiconductive material is formed from a primary substrate including a single crystal or several very large crystals of a relatively low-melting material. This primary substrate is deposited on a base such as steel or ceramic, and it may be formed from such metals as zinc, cadmium, germanium, aluminum, tin, lead, copper, brass, magnesium silicide, or magnesium stannide. These materials generally have a melting point below about 1000.degree. C. and form on the base crystals the size of fingernails or greater. The primary substrate has an epitaxial relationship with a subsequently applied layer of material, and because of this epitaxial relationship, the material deposited on the primary substrate will have essentially the same crystal size as the crystals in the primary substrate.

Abstract: Disclosed is a method and apparatus for growing in a gravitational field a microscopic crystal from a solution. Solution is held in a vertical chamber which is relatively thin, the thin dimension being generally perpendicular to the vertical. There is a substrate crystal disposed at either the upper or lower end of the chamber and the crystal grows from this substrate crystal in one direction. In accordance with this invention, the temperature conditions of the solution are controlled so that as the crystal forms the effects of buoyant convection within the solution are minimized. This is accomplished in two different ways depending upon whether the crystal is grown from the upper or lower end of the chamber. When grown from the upper end of the chamber, the temperature of the solution is controlled so that it remains essentially isothermal so that there is essentially no heat loss from the solution.

Abstract: Crystals (51) of high morphological quality are grown by dissolution of a substance (28) to be grown into the crystal (51) in a suitable solvent (30) under high pressure, and by subsequent slow, time-controlled reduction of the pressure of the resulting solution (36). During the reduction of the pressure interchange of heat between the solution (36) and the environment is minimized by performing the pressure reduction either under isothermal or adiabatic conditions.

Abstract: Electrodes (18) are positioned in intimate contact with an outer surface of a thin electrically-insulating protecting layer (16) of architectural reflective glass (20). Application of a voltage of sufficient magnitude substantially destroys the insulating layer (16) located beneath the electrodes (18). A subsequent application of voltage results in a passage of current through the underlying thin, light-reflective metal or metal oxide layer (14) and in concomitant output of heat.

Abstract: An assembly (28) of ceramic surfaces (21, 23), particularly refractory metal oxides and carbides, abutting a thin sheet (22) of metal susceptor material are placed in a chamber (10) of an enclosure (14) containing inert gas (36). An r.f. coil (24) is activated by power supply (26) to melt the susceptor (22) and adjacent zones (40, 42) of the ceramic. Reactive gas such as oxygen or a carbonizing gas (38) is then fed to the chamber (10) and reacts with the susceptor (22) to form compounds (47) which disperse and dissolve in the zones (40, 42). On cooling, a strong joint is formed. The susceptor may contain inner perforations (58) and outer perforations (56) to aid in distribution of heat.

Abstract: A process for the purification of molten materials during crystal growth by electromigration of impurities to localized dirty zones. The process has particular applications for silicon crystal growth according to Czochralski techniques and edge-defined film-fed growth (EFG) conditions. In the Czochralski crystal growing process, the impurities are electromigrated away from the crystallization interface by applying a direct electrical current to the molten silicon for electromigrating the charged impurities away from the crystal growth interface.In the EFG crystal growth process, a direct electrical current is applied between the two faces which are used in forming the molten silicon into a ribbon. The impurities are thereby migrated to one side only of the crystal ribbon. The impurities may be removed or left in place. If left in place, they will not adversely affect the ribbon when used in solar collectors.