초록 ▼

Processes for the continuous preparation of single crystals having a predetermined shape and requiring little or no subsequent machining which processes comprise placing a single crystal-forming material in a crucible fitted in its lower portion with a capillary conduit having a length equal to or g

Processes for the continuous preparation of single crystals having a predetermined shape and requiring little or no subsequent machining which processes comprise placing a single crystal-forming material in a crucible fitted in its lower portion with a capillary conduit having a length equal to or greater than the retention length of the molten material in the capillary at the selected temperature and pressure, heating the crystal-forming material to a temperature above its melting point, bringing a performed appropriately oriented crystal seed into contact with the pendant drop formed at the lower point of the capillary, and pulling the seed crystal away from the feed material in the crucible so that the amount of crystal-forming material fed per unit of time is at every instant substantially equal to the quantity of material pulled into single crystal form, together with novel apparatus comprising a capillary-containing crucible, heating means, feed means, enclosure, seed-supporting carrier, means for moving and rotating the carrier, and means for controlling the movement of the carrier.

대표청구항 ▼

A continuous process for the preparation of single crystals having a predetermined shape, which process comprises: (a) charging the crystal-forming material to a crucible tapped in its lower region by a capillary conduit with a height greater than or equal to the retention height of the melted cryst

A continuous process for the preparation of single crystals having a predetermined shape, which process comprises: (a) charging the crystal-forming material to a crucible tapped in its lower region by a capillary conduit with a height greater than or equal to the retention height of the melted crystal-forming material in the capillary at the temperature and pressure used, (b) bringing th crystal-forming material to a temperature above its melting point so as to form a drop at the lower end of the capillary, (c) contacting a preformed seed crystal having a selected crystal orientation with the drop, and (d) pulling the seed crystal in contact with the drop downwardly away from the crucible to form a single crystal, at a growth front between the crystal and the melted crystal-forming material, the quantity of crystal-forming material fed per unit of time being substantially equal to the amount of material pulled into the single crystal and the force at the growth front being substantially nil.