Transmission electron microscope study of xenon implanted into metals

Abstract Recent investigations of rare gases in metals have shown that argon, xenon and krypton implanted into aluminium tend to cluster and form small overpressurized precipitates exhibiting a f.c.c. crystallographic structure. In the present work electron microscopy diffraction patterns were used to perform a systematic study of the crystallographic structure of xenon precipitates in several metals. It was found that Xe crystalline precipitates are always epitaxially orientated in the host metallic f.c.c. lattice and overpressurized. The pressure in the xenon clusters was determined from a state equation relating pressure to the atomic volume. An attempt to compare Xe clustering to the well known pre-precipitation process in aluminium alloys allowed the presence of streaks in 〈111〉 directions of the reciprocal lattice to be attributed to the clustering of Xe atoms into platelets parallel to close-packed planes of the matrix.