The growth of dome-shaped sapphire crystals by the gradient solidification method (GSM)

Sapphire Crystal Growth and Applications

“…There are some other modifications of VBT-the temperature gradient technique TGT [32] and the gradient solidification method GSM [33]. The last technique was successfully used for dome growth by shaping of the crucibles.…”

“…The effort of production is concerned with minimization of the treatment by growth of crystals having a shape close to a dome. There are some successful examples of this kind: GSM diameter to 150 mm [33], noncapillary feeding diameter to 80 mm [40], local shaping technique [41], modified EFG diameter to 40 mm [42].…”

Problems and recent advances in melt crystal growth technology

“…In addition, it should be also mentioned the using (in less extent) Czochralski [24], gradient solidification method (GSM) [25] and temperature gradient technique (TGT) [26]. The main difference between the HEM versus GSM and TGT is that the thermal field of the furnace in the GSM and TGT systems contains upward temperature gradients [27].…”

Shaped Crystal Growth

“…A new approach to producing sapphire at reduced cost is to grow a near -net -shaped crystal. Methods for the preparation of near -net shapes directly in the course of the growth process by the heat exchange method (HEM) [Khattak 1989, Khattak 1992 , the gradient solidifi cation method (GSM) [Horowitz 1993, Horowitz 1996] and the modifi ed EFG method [Locher 1990, Locher 1992] have been reported. NCS is another technique that can be used to produce sapphire domes.…”