A crucible is provided that is thermally stable at high temperatures and is suitable for use in the growth of large, bulk AlN, AlxGa1-xN or other nitride single crystals. The crucible is comprised of specially treated tantalum. During the initial treatment, the walls of the crucible are carburized, thus...http://www.google.de/patents/US7056383?utm_source=gb-gplus-sharePatent US7056383 - Tantalum based crucible
