Monocrystal leucosapphire growing facility per Kyropoulous method (Musatov, Goi)

Kyropoulous method was applied for the first time in 1970s in the Soviet Union to grow sapphire crystals. In 1990s this method was improved by Dr. Musatov and was named the GOI method.

Kyropoulousmethod implies that the entire volume of raw material is crystallized within a boule. The size and proportion of sidewalls of the crucible are close to those of final crystal; the latter is growing downwards to the crucible. The upward extension of the seed (proposed by Musatov M.I.) is much slower than the downward crystal growing. This mechanism is crucial to form a convex-concave lens within crystal-liquid boundary via superficial tension.

The growth speed is managed through slowly decreasing temperature until the hot melt is crystallized. Once the seed is hanged to the sensor, the feedback to define the growth speed is thus secured.

The entire process is carried out in argon plume or in high vacuum.

The NPO “GKMP” LLC delivers machines designed for growing of leucosapphire crystals and other materials by Kyropoulous method. Our facilities are capable to grow crystals up to 65 kg. Our machines are based on out-of-the-box solutions of current feed through location and cover of the chamber. The column is equipped with the 500 kg telpher. Technologists that took part in development of our products highly estimated the benefits of such modification.

The facilities are equipped with advanced control system in order to: ensure the proper heater current, voltage and power measurement, perform pressure control inside the chamber and roughing line, control rotation and travel of the rod, perform measurements of cooling water pressure and flowrate in each loop, measure the mass of the crystal, send alarm signals etc.

The hardware is manufactured on request under approved Technical assignment. Any parameters can be changed at your convenience.

Benefits of machines for growing of monocrystals per Kyropoulous method produced by the “NPO “GKMP” LLC

• One cover – protects from leakage, provides more convenient access to perform maintenance of the thermal assembly and cleaning of the chamber.
• Lateral location of current feedthroughs – the operator is not exposed to electromagnetic radiation.
• The column is equipped with the telpher that simplifies extraction of the crystal and crucible from the machine. Moreover, it enables to assemble and disassemble the chamber and thermal screens without overhead crane or elevator whatsoever.

Property	Meaning
Crystal growing method	Kyropoulous KY(GOI)
Mass of the crystal, kg	Up to 65
Diameter * height of the crucible, mm	350 * 500
Diameter * height of the chamber, mm	800*1000
Chamber material	12Х18Н10Т
Upper rod stroke, mm	400
Rod travel speed, mm/h	0.1… 10.0
Rod rotation, r/min	1-20
Heating method	Resistive
Heater material	Tungsten
Heater power, kW	Up to 60
TV sensor	On request
Pyrometers and thermocouples	On request
Vacuum, torr	Up to 5х10-5
Operating in argon	Available
Electric power parameters	3*(380±38)+N