A Grain Boundary Model of Hexagonal Crystals

—With Special Reference to the G. B. Properties in Ice—

Abstract

Relationships between the rotation angle θ and the reciprocal density of coincident sites Σ in the coincidence site lattice (CSL) model for the ideal hexagonal crystal in which the axial ratio c/a=√8/3 were calculated for three rotation axes of low indices: [0001], [1210] and [1010] . For determining the Burgers vectors of grain boundary dislocations, the displacement shift complete (DSC) lattices were also calculated for the above cases. Results of the calculations in the range of Σ<50 were tabulated in Tables 2-4 besides the generating equations in Table 1. The structure and behavior of grain boundaries in ice crystals, especially those found experimentally by the present authors with artificially grown ice bicrystals of <1010 >/34°were well explained by the model presented above.