Misorientation dependence of atomic structure and energy of symmetric tilt boundaries in magnesium

Abstract

ABSTRACTTwelve symmetric tilt boundaries in magnesium spanning misorientation range 78.29° ≤ θ ≤ 145.85° are investigated with molecular dynamics simulation at 0 K, using an embedded-atom method. Three favoured boundaries are identified in this range: 78.29°, 116.88° and 145.85°. Boundary structures intermediate between the first two boundaries are predicted by the structural unit model, which cannot be applied, however, to the misorientation range 116.88° < θ < 145.85°. A sharp transition between the structural units of the 116.88° and 145.85° boundaries is observed within the narrow misorientation range 135° < θ < 138° at or close to the energy maximum. The transition is obviously caused by avoidance of long-range compatibility stresses between these units.