Study of model of self-coordinated growth of single crystals of sapphire by horizontal directed crystallization

Physical and Technological Fundamentals of Sapphire Substrates Production for Devices of Solid-state Electronics

“…As a result, the stresses in the crystal can be formed. Their intensity is determined by the temperature distribution [11]:…”

“…The modes of mechanical treatment significantly affects the defects distribution concentration [11,12]. The depth of the damaged layer was calculated.…”

Analysis of heat transfer processes for sapphire growth by horizontal directed crystallization method

“…The HDC is one of the most widespread method for sapphire crystals growth from melt. [1][2][3][4][5][6] During crystallization, the shape of the crystal has a significant effect on the sapphire crystal growth and defects formation. The study of the structure formation process, impurity distribution, and the nature of the defects appearing in the crystal volume during growth are particularly interesting because sapphire crystals obtained by the HDC method have a characteristic configuration at the initial and subsequent stages of growth.…”

Microstructural Evolution in α-Al2O3 Compacts During Laser Irradiation

“…However a part of intergranular voids are encapsulated. Under complete melting of the material, these microvoids cause the blistering of the melt and remain in the volume of the material during its crystallization (Dobrovinskaya et al, 2009;Malukov et al, 2008). The formation of large pores and damages in the upper part of the rod (on an irradiation surface) is predominantly caused by the development of hightemperature processes of dissociation of Al 2 O 3 (Ristic et al, 2009;Pankratz, 1982).…”

“…To obtain a strictly oriented monocrystals, a seeding agent is placed in the top of boat, after which both the moment of crystallization and the shape of the crystallization front in the process of monocrystal growth is monitored. The thermophysical processes play a decisive role in the crystallization of high-quality monocrystals because they are responsible for the generation of substantial internal mechanical stresses, porosity, and high dislocation density (Bagdasarov & Goryainov, 2001;Bagdasarov & Goryainov, 2007;Denisov et al, 2007;;Dobrovinskaya et al, 2009;Lukanina et al, 2006;Malukov et al, 2008). In recent years, along with traditional powder metallurgy methods for the synthesis of corundum ceramics, SLS has been used (Liu et al, 2007;Shishkovsky et al, 2007;Subramanian & Marcus, 1995;Subramanian et al, 1993;Xu et al, 2005), what makes it possible to combine complete and partial melting in a single cycle.…”