An analysis of high-resolution transmission electron microscopic images of the microstructures of monoclinic films revealed that some areas were built up entirely of twins, and that their boundaries formed triple and quadruple junctions. Whereas the misorientations of the constituent boundaries were completely balanced at quadruple junctions, there was a small rotational mismatch at the junctions of 3-twin boundaries. This mismatch was compensated by wedge disclinations. The factors which stabilized intrinsic junction disclinations were considered with regard to the crystallography of the triple junctions.

Twin Junctions in Monoclinic Zirconia. V.Y.Gertsman: Interface Science, 1999, 7[3-4], 231-42