Melting and misalignment of solid crystalline krypton inclusions in aluminum

Abstract

Ion-implantation–induced crystalline krypton inclusions in aluminum, epitaxially aligned with the matrix, have been investigated with x-ray diffraction and Rutherford-backscattering channeling analysis. The data show a dual size distribution of the krypton bubbles. In samples annealed up to 620 K and subsequently cooled, the larger bubbles melt in a pressure-broadened transition at 114–118 K. The smaller bubbles remain solid upon heating but, as a result of a roughening transition on the aluminum facets of the cavities, the Kr crystallites gradually lose their epitaxial alignment.