Ion-Beam-Induced plastic deformation: A universal behavior of amorphous solids

Homogeneous irradiation of amorphous materials with a high energy heavy ion-beam results in visible growth of the sample dimensions perpendicular to and shrinkage of the sample dimension parallel to the ion beam. The quantitative details of this effect are remarkably similar although the investigated materials belong to completely different classes of amorphous solids. A simple relation is derived which explains this universal behavior.