Edge-defined film-fed growth of beta-alumina and Mg-substituted beta-alumina

High Na vapor pressure, peritectic decomposition, and high reactivity of the melt complicate the growth of beta-alumina crystals. These difficulties were overcome by using a high-pressure (300 psig) growth chamber, Na2O-rich melts, and Ir for all surfaces in contact with the melt. These procedures were combined with the edge-defined film-fed growth technique to produce single-crystal beta-alumina tubes and ribbons.