Effects of the diameter of rutile (TiO2) single crystals grown using tilting-mirror-type infrared heating image furnace on solid–liquid interface and etch pit density

The difficulties in growing large-size bulk β-Ga2O3 single crystals with the Czochralski method were numerically analyzed. The flow and temperature fields for crystals that were four and six inches in diameter were studied. When the crystal diameter is large and the crucible space becomes small, the flow field near the crystal edge becomes poorly controlled, which results in an unreasonable temperature field, which makes the interface velocity very sensitive to the phase boundary shape. The effect of seed rotation with increasing crystal diameter was also studied. With the increase in crystal diameter, the effect of seed rotation causes more uneven temperature distribution. The difficulty of growing large-size bulk β-Ga2O3 single crystals with the Czochralski method is caused by spiral growth. By using dynamic mesh technology to update the crystal growth interface, the calculation results show that the solid–liquid interface of the four-inch crystal is slightly convex and the center is slightly concave. With the increase of crystal growth time, the symmetry of cylindrical crystal will be broken, which will lead to spiral growth. The numerical results of the six-inch crystal show that the whole solid–liquid interface is concave and unstable, which is not conducive to crystal growth.

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DIFFUSION OF Tl+ IONS THROUGH THE INTERFACE OF SOLID NaCl, KCl OR RbCl AND LIQUID TlCl

International Journal of Modern Physics B ◽

10.1142/s0217979202009524 ◽

2002 ◽

Vol 16 (01n02) ◽

pp. 108-113

Author(s):

W. YU ◽

A. FUJII

Keyword(s):

Sodium Chloride ◽

Single Crystals ◽

Optical Method ◽

Diffusion Constant ◽

Liquid Interface ◽

Diffusion Constants ◽

Diffusion Phenomena ◽

Diffusion Source ◽

Solid Liquid Interface ◽

Solid Liquid

The diffusion phenomena of thallous ions ( Tl + ions) through solid-liquid interface of liquid Tl + ions diffusion source and sodium chloride (NaCl) , potassium chloride (KCl) or rubidium chloride (RbCl) single crystals are studied by optical method. The characterisic absorption peaks of Tl + center in NaCl, KCl or RbCl single crystals were used as the tracer for measurements and the diffusion constants are evaluated at various temperatures. The results show that the diffusion constant of solid-liquid interface is about 103 times larger than that of solid-solid interface of KCl and TlCl .

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High Quality CdTe Growth by Gradient Freeze Method

MRS Proceedings ◽

10.1557/proc-90-111 ◽

1986 ◽

Vol 90 ◽

Cited By ~ 22

Author(s):

A. Tanaka ◽

Y. Masa ◽

S. Seto ◽

T. Kawasaki

Keyword(s):

Liquid Interface ◽

Subgrain Structure ◽

High Electron ◽

Interface Shape ◽

High Quality ◽

X Ray ◽

Etch Pit ◽

Infrared Measurements ◽

Solid Liquid Interface ◽

Solid Liquid

ABSTRACTThe vertical Bridgman method, a gradient freeze technique, is feasible for the growth of high quality, large CdTe crystals. The equi-composition contour of Zn in doped crystals has been used to reveal the solid-liquid interface shape in the growth process. A slow cooling rate is necessary to obtain a convex interface shape. A low temperature gradient at the solid-liquid interface, down to 2 °C/cm, and Zn doping are found to be effective to reduce the etch pit density to 5×103/cm2 (minimum) to 104/cm2 (average). The crystallographic quality has been evaluated by means of X-ray diffraction, X-ray topography, etch pit delineation with the Nakagawa etchant, infrared measurements, photoluminescence and Hall effect measurements. CdTe crystals are found to be free from subgrain structure, Te precipitates and deep levels, and have high electron mobility.

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