@phdthesis{Tavakoli2006, author = {Tavakoli, Mohammad Hossein}, title = {Numerical analysis of seeding process during Czochralski growth of oxide single crystals}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:co1-opus-145}, school = {BTU Cottbus - Senftenberg}, year = {2006}, abstract = {A series of two-dimensional and three-dimensional quasi-steady state numerical simulations have been performed for the initial stages (seeding process) of the Czochralski (CZ) growth of oxide crystals using the finite element method (FEM). We have considered different cases and configurations with respect to real systems in the CZ-dielectrics laboratory of the Institute for Crystal Growth (IKZ). Using induction heating in metallic parts as heat source the fluid flow and temperature field were determined in the whole CZ system. The aim of these calculations was to investigate and reveal the effect of several parameters such as the geometry and location of an active afterheater with respect to the crucible, arrangement and design of thermal insulation, crucible bottom shape, and seed rotation rate on the flow and temperature field of the system and the seed-melt interface shape. The results demonstrate that the temperature and fluid flow in the gas domain is strongly affected by an active afterheater and its insulation as well as their geometry and position. The results also show the important role played by the seed rotation rate for influencing the shape of the seed-melt interface.}, subject = {Kristallz{\"u}chtung; Czochralski-Verfahren; Czochralski-Verfahren; Ankeimprozess; Temperaturverteilung; Kristallz{\"u}chtung; Czochralski method; Seeding process; Heat transfer; Induction heating}, language = {en} }