Premium
3D simulation of the effects of growth parameters on the growth of sapphire crystals using heat exchanger method
Author(s) -
Lu ChungWei,
Chi PeiHung
Publication year - 2007
Publication title -
crystal research and technology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.377
H-Index - 64
eISSN - 1521-4079
pISSN - 0232-1300
DOI - 10.1002/crat.200711015
Subject(s) - crucible (geodemography) , crystal (programming language) , micro pulling down , anisotropy , heat exchanger , materials science , convection , sapphire , conductivity , crystal growth , mechanics , thermal conductivity , optics , chemistry , thermodynamics , composite material , crystallography , physics , laser , computational chemistry , computer science , programming language
3D simulations using the commercial CFDRC and FIDAP code, which are based on finite element techniques, were performed to investigate the effects of anisotropic conductivity on the convexity of the melt–crystal interface and the hot spots of sapphire crystal in a heat‐exchanger‐method crystal growth system. The convection boundary conditions of both the energy input to the crucible by the radiation as well as convection inside the furnace and the energy output through the heat exchanger are modeled. The cross‐sectional flow pattern and the shape of the melt–crystal interface are confirmed by comparing the 3‐D modeling results with previous 2D simulation results. In the 3D model, the “hot spots” in the corners of the crucible are donut shaped, and the shape changes with the value of the conductivity of anisotropic crystal. The outline of the crystal becomes more convex as the conductivity in the z direction ( k sz ) increases. The outline of melt–crystal interface is elliptical when the anisotropic conductivity is moving in the radial direction ( k sx and k sy ). The portion at the outline touching the bottom of the crucible is smaller than the maximum outline of the crystal, meaning that the shape at the “hot spot”, changes with the value of the conductivities of anisotropic crystal. (© 2007 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)