Distribution of Grain Boundary Planes and Misorientations in Magnesium Oxide

We have developed a technique that allows the geometry and crystallography of large quantities of contiguous crystallites to be accurately characterized. Using this technique, in concert with high precision serial sectioning, we have extracted the geometric and crystallographic configuration of approximately 2.5 mm of grain boundary area in a 0.33 mm volume of polycrystalline magnesium oxide. Using these data, we have specified the distribution of grain boundaries within the five-dimensional space of misorientation and inclination types. The data show that in addition to the texture in the misorientation space induced by processing, there is texture in the space of grain boundary planes. For example, for 5 ° misorientations about <111>, pure twist and tilt boundaries occur more frequently than general boundary plane configurations.