Structural rotation of Al under uniaxial compression: A first-principles prediction

We report on a density functional theory based study of a novel structural rotation of single-crystal aluminum (Al) under uniaxial compression. It was found that under strains either along the 〈112〉 or the 〈111〉 direction, beyond a critical stress of about 13 GPa, the Al crystal can rotate through shear in the Shockley partial direction on the {111} plane, to relieve internal stresses. This phenomenon reveals a new mechanism leading to the onset of homogeneous dislocation nucleation in face-centered-cubic materials under high uniaxial compressions.