Occurrence of solid noble-gas inclusions in ion-beam-implanted magnesium oxide

Ion implantation of xenon into single-crystal magnesium oxide results in the formation of solid, crystalline xenon inclusions. These inclusions have been investigated by transmission electron microscopy and selected-area diffraction. The solid inclusions could be divided into two categories: those that were epitactically aligned with the matrix and those that were randomly oriented. The formation of solid inclusions at room temperature indicates that they were under a high pressure. This pressure was calculated to be 0.40.6 GPa. © 1991 The American Physical Society.