Flame-Fusion Verneuil Growth of Oxides

the flame-fusion process is a crucible-free crystal growth process for high-melting compounds, an economic process that allows control of nucleation and crystal diameter within a relatively simple apparatus, and was a signiflcant breakthrough achieved by Auguste Verneuil around 1900. 

Crptal Growth Technology. Edited by Hans J. Scheel and Peter Capper Copyright 2008 WILEY-VCH Verlag GmbH Co. KGaA, Weinheim ISBN 978-3-527-31762-2 

8) muffle kiln with a viewing port, 9) crystal, 10) crystal support with rotation and withdrawal mechanism. 

Hydrogen-oxygen flame with feed powder 

industrial ruby production started in the Paris laboratory of the L. Heller and Son Company of New York and the company H. Djevahirdjian in Paris. Verneuil also solved the problem of the blue color of sapphire that he found to be due to the combined presence of iron and titanium [38, 42]. 

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The Verneuil, or flame-fusion, method is illustrated in Figure 29.1. It is a well-established technique for growing single crystals of oxides that have high melting temperatures. The largest application of the Verneuil method is for the growth of sapphire and ruby. 

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