Geometrical and crystallographic data, obtained from a well-annealed polycrystal, were used to identify the 5 macroscopic degrees of freedom of 4665 grain boundaries. The results indicated that the 5-parameter grain boundary character space was fully occupied. A finite series of symmetrized spherical harmonics was used to approximate the misorientation dependence of the relative grain boundary energy. Best-fit coefficients for this series were determined by assuming that the interfacial tensions at each triple junction were balanced. The grain-boundary energy-function exhibited Read-Shockley behavior at small misorientations, and a broad minimum near to the Σ = 3 misorientation. Misorientations about the (100) axis created boundaries having relative energies that were lower than those created by misorientations about the (110) or (111) axes.

Misorientation Dependence of the Grain Boundary Energy in Magnesia. D.M.Saylor, A.Morawiec, B.L.Adams, G.S.Rohrer: Interface Science, 2000, 8[2-3], 131-40