Suppression of crystal growth instabilities during production of rare-earth oxyorthosilicate crystals
AssigneeSiemens Medical Solutions USA, Inc.
InventorsMark S. Andreaco, A. Andrew Carey, Piotr Szupryczynski
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Abstract
Disclosed are a method of growing a rare-earth oxyorthosilicate crystal and a crystal grown using the method. A melt is prepared by melting a first substance including at least one rare-earth element and a second substance including at least one element from group 7 of the periodic table. A seed crystal is brought into contact with the surface of the melt and withdrawn to grow the crystal.
Claims20
A composition comprising a rare-earth oxyorthosilicate crystal having a composition described by L2A2yR2(1-x-y)SiO5, where R represents at least one first rare-earth element, L represents at least one second rare-earth element, A represents at least one group 7 element and optionally at least one group 2 element, 0<x≦10% and 0<y≦10%, and 0.005≦(y/x)≦5.0, the crystal being made by a process comprising:
- preparing a melt by:
- melting a first substance comprising at least one first rare-earth element;
- and
- melting a second substance comprising at least one element from group 7 of the periodic table;
- melting a substance comprising silicon;
- providing a seed crystal;
- contacting the surface of the melt with the seed crystal;
- withdrawing the seed crystal from the melt to obtain a crystal boule;
- and
- obtaining from the boule a crystal.
A material comprising a scintillation crystal with a composition described by L2xA2yR2(1-x-y)SiO5, where R represents at least one first rare-earth element, L represents at least one second rare-earth element distinct from the first rare-earth element, A represents at least one group 7 element, wherein 0.00001≦x≦0.1;
- and 0.00001≦y≦0.1.
A material comprising a scintillation crystal with a composition described by L2xA2yR2(1-x-y)SiO5 where R re resents at least one first rare-earth element, L represents at least one second rare-earth element distinct from the first rare-earth element, A represents at least one group 7 element 0<x≦10%, 0<y≦10%, and 0.005≦(y/x)≦5.0.
A single crystal scintillation material with a composition described by L2A2yBzR2(1-x-y)SiO5, where R represents at least one first rare-earth element, L represents at least one second rare-earth element distinct from the first rare-earth element, A represents at least one group 7 element and includes manganese, B represents at least one element from group 2 of the periodic table of element, 0<x≦10%, 0<y≦10%, z≧0 and 0.005≦(y/x)≦5.0.
Dependencies are inferred from the claim text.