High pressure apparatus and method for nitride crystal growth

A method of crystal growth, the method comprising:

• providing an apparatus for high pressure crystal or material processing, the apparatus comprising:
• a cylindrical capsule opening for retaining a capsule having a length;
• an annular heating member having a length and an outer diameter, and surrounding at least a portion of the length of the capsule opening;
• a radial heater restraint surrounding at least a portion of the length of the annular heating member, the radial heater restraint comprising a high strength enclosure;
• and
• an annular gap defined by the outer diameter of the annular heating member and the inner diameter of the radial heater restraint, wherein the annular gap is at least 0.010 inch at room temperature and is configured to provide a radial load-bearing contact between the annular heating member and the radial heater restraint at a temperature not less than about 100 degrees Celsius;
• providing a capsule containing a solvent;
• placing the capsule within an interior region of the cylindrical capsule;
• and
• processing the capsule with thermal energy to cause an increase in temperature within the capsule to be greater than 200 Degrees Celsius and to cause the solvent to be superheated.

A method of crystal growth, the method comprising:

• providing an apparatus for high pressure crystal or material processing, the apparatus comprising:
• a cylindrical capsule opening for retaining a capsule having a length;
• a metal capsule disposed within the capsule opening, wherein the metal capsule contains ammonia and a mineralizer;
• an annular heating member having a length and surrounding at least a portion of the length of the capsule opening;
• and
• a radial heater restraint surrounding at least a portion of the length of the annular heating member, the radial heater restraint comprising a high strength enclosure, the radial heater restraint comprising at least one crack;
• providing a capsule containing a solvent;
• placing the capsule within an interior region of the cylindrical capsule;
• and
• processing the capsule with thermal energy to cause an increase in temperature within the capsule to greater than 200 Degrees Celsius and to cause the solvent to be superheated.

An apparatus for high pressure material processing comprising:

• a cylindrical capsule opening for retaining a capsule having a length;
• an annular heating member having a length and an outer diameter, and surrounding at least a portion of the length of the capsule opening;
• a radial heater restraint surrounding at least a portion of the length of the annular heating member, the radial heater restraint comprising a high strength enclosure;
• and
• an annular gap defined by the outer diameter of the annular heating member and the inner diameter of the radial heater restraint, wherein the width of the annular gap is selected to provide a first radial load-bearing contact between the annular heating member and the radial heater restraint at a temperature not less than about 100 degrees Celsius.