Growth method for sapphire crystal

There are two commonly used growth methods for sapphire crystal:

1: Czochralski method (CZ method for short) : Firstly, the raw materials are heated to the melting point and then melted to form the melt soup; then, a single crystal seed is used to contact the surface of the melt soup, and the solid liquid interface between the crystal seed and the melt soup is reached

Supercooling is caused by temperature difference.So the melt begins to solidify on the seed surface and grow single crystals with the same crystal structure as the seed.At the same time, the seed is pulled up at a very slow speed and rotates at a certain speed. As the seed is pulled up, the molten soup gradually solidifies on the liquid-solid interface of the seed, thus forming an axisymmetric single crystal lake.

2: the kjeldahl method of long jing (Kyropoulos method), referred to as "new method, the mainland is called the foam body. Its principle and Chai Shi crystal pulling method (Czochralskimethod) similar to the first heating materials to flame point after Mr Taxiing ChengPei soup, and then to single crystal seed (SeedCrystal, also known as the seed crystal rods) come into contact with the melt the surface of the soup of solid-liquid interface in the crystal seed and molten soup began to grow on the same crystal structure of single crystal wafer, seed to pull up very slowly, but in the seed crystal crystal pulling up a period of time to form a neck,When the solidification rate of the interface between the melt soup and the seed is stable, the seed will no longer be pulled up or rotated, but the single crystal can be gradually solidified from the top to the bottom by controlling the cooling rate, and finally solidified into a whole single crystal.

The crystal growth diagram of the two methods is as follows: