Synthesis of beryl crystals
AssigneeKabushiki Kaisha Suwa Seikosha
InventorKatsuhiro Teraishi
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Abstract
A method for synthesizing beryl crystals from a raw material substantially that of natural beryl and at least one material of molybdates, vanadates and tungstates to form a flux is provided. The raw material and oxides are melted and a rotating beryl seed crystal is placed in contact with the rotating melt zone and drawn away from melt zone so that beryl crystal is synthesized as the seed crystal is withdrawn from the melt zone. The melt zone may be formed in a zone floating furnace with rotating axes or in a rotating crucible.
Claims15
A method of synthesizing beryl single crystals in a zone floating apparatus, comprising:
- forming a raw material powder by mixing beryllium oxide (BeO), aluminum oxide (Al.sub.2 O.sub.3), silicon dioxide (SiO.sub.2) and chromium oxide (Cr.sub.2 O.sub.3) in a molar ratio substantially that of natural beryl, said raw material having the composition, 3BeO.Al.sub.2 O.sub.3.6SiO.sub.2.0.005Cr.sub.2 O.sub.3 ;
- sintering the raw material powder and forming a feed rod;
- mounting the feed rod on a first rotating axis and rotating the feed rod in a first rotational direction;
- forming a flux pellet of raw material powder including at least one material selected from the group consisting of molybdates, vanadates and tungstates;
- placing the flux pellet on the free end of the feed rod;
- forming a melt zone in the free end of said rotating feed rod;
- mounting a seed crystal on a second rotational axis and rotating said axis in a direction opposite to the first rotation direction;
- contacting the rotating seed crystal with the melt zone including the flux pellet;
- moving the melt zone along the feed rod so that beryl crystal is synthesized as the melt zone is displaced along the feed rod;
- and
- heating said synthetic crystal at a temperature of between about 1000.degree.-1410.degree. C. for about 50 to 500 hours.
Dependencies are inferred from the claim text.