Growth of High-Purity and Doped Alkaline Earth Oxides: I. MgO and CaO

A new variation of the carbon arc-fusion technique is reported which makes possible the growth of large, high-purity MgO and CaO single crystals which are free of microbubbles. A technique has also been developed for impurity doping. We have successfully doped MgO with Na, D, Ce, Eu, Gd, Dy, and Yb; and CaO with Li, Na, Ce, and Nd. The presence of these dopants has been ascertained by chemical analyses, optical, or EPR measurements. EPR signals showed minimal effects from strains in these crystals.