  Bulk crystals of zinc oxide can be grown from the melt by a Bridgman
technique under pressure. This new technology using an iridium crucible shows
the potential to yield large single crystals of good crystalline perfection.
Crystals with diameters up to 33 mm and a length of up to 50 mm have been
demonstrated. The impurity content can be strongly reduced by using the
crucibles repeatedly.
