Growth of long-length sapphire rods of optical quality

• Видавець: НТК «Інститут монокристалів» НАН України
• Дата: 2005
• Автори: Andreev, Yu.P., Kryvonosov, Yu.V., Lytvynov, L.A., Vyshnevskiy, S.D.
• Формат: Стаття
• Мова: English
• Опубліковано: НТК «Інститут монокристалів» НАН України 2005
• Назва видання: Functional Materials
• Онлайн доступ: http://dspace.nbuv.gov.ua/handle/123456789/140084
• Цитувати: Growth of long-length sapphire rods of optical quality / Yu.P.Andreev, Yu.V.Kryvonosov, L.A. Lytvynov, S.D. Vyshnevskiy // Functional Materials. — 2005. — Т. 12, № 1. — С. 142-146. — Бібліогр.: 10 назв. — англ.

The technological possibilities of the growth of optical-quality sapphire rods with a diameter of 12...20 mm and a length of 500...1000 mm by the Stepanov method. The influence of crystallization rate and crystallographic growth direction on the optical quality of the crystals was investigated. The technological procedure of "cold" narrowing of the growing crystal at the beginning stage of seeding was proposed to improve crystals structure. It was shown that heat treatment of the grown crystal in a gas environment with neutral chemical potential leads to destruction of optical color centers and scattering foreign-phase inclusions in its volume. It was shown that the main reason of color and scattering centers foundation in sapphire is anionic stoichiometry violation and the presence of uncontrollable impurities in the melt._To obtain long sapphire rods of optical quality the crystallographic oriented growth [1120] is preferred. In the process of growing a rod with a diameter of 14 mm, the depth of the surface-adjacent defective layer does not exceed 0.4 mm and the small-angle optical scattering doesn’t have to be greater than 0.01 cm⁻¹.