Single-crystal growth of magnesium oxide by the flux method

Abstract

Crystals of magnesium oxide were grown from solution in a 7MgO.5WO 3.Na 2O.P 2O 5 melt by the temperature gradient method. Parallelopipeds with {100} faces up to 7 mm on edge were grown in 5–6 days from a 75–100 ml nickel crucible protected by an argon atmosphere. None of the major flux constituents was detected in a semi-quantitative spectrographic analyses of the crystals. The crystals were transparent up to 9.3 microns in the infrared. The dislocation density of the as grown crystals was of the order of 5×10 4/cm 2. The critical resolved shear stress, as found from indentation wing size measurements, was of the order of 6.0 kg/mm 2.