Characterization of defects in nickel-doped MgO crystals

Heavily Ni-doped magnesium oxide crystals, grown by the arc-fusion technique, have been investigated using optical and transmission electron microscopy to examine the dislocation content, sub-boundaries, and impurity precipitates. Yield stress measurements were also made. Dislocation structures and impurity precipitates at the sub-boundaries are described, and their implications concerning the use of these crystals as laser materials are discussed