The HDS method
“Horizontal directional solidification method” created by Kh.S.Bagdasarov in 1964 was new radical idea of single crystal growth based on moving a crucible with the raw material and a single crystal seed in the horizontal direction. This method was created for the growth of large-size, Nd doped, high-perfect yttrium-aluminum garnet laser crystals. It turned out to be very efficient for sapphire growth too creating crystals with previously unseen surface areas. Using the HDS method issues of synthesis of large and especially large plate-form refractory leucosapphire single crystals were solved.
The HDS methods growth process consist of the following process’s
The HDSM method allows to carry out repeated crystallization in case when additional chemical purification of the raw material is required. It is also possible to carry out a continuous crystallization process by directed shift of the crucible echelon through the crystallization zone. While realizing the HDSM method it is technically easy to create a controlled temperature field that is extremely necessary for growth of high-perfect large-size single crystals. This method makes it possible to get large slabs with almost perfect edges and of any given crystallographic orientation