Browsing by Author "Kluth, SM"

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Ion-irradiation-induced porosity in GaSb and InSb
    (Australian Institute of Physics, 2005-01-31) Kluth, SM; Johannessen, B; Kluth, P; Glover, CJ; Foran, GJ; Ridgway, MC
    Ion irradiation of crystalline GaSb and InSb can yield not only amorphisation, as commonly observed in semiconductors, but also porosity. Extended x-ray absorption fine structure spectroscopy, electron microscopy and Rutherford backscattering spectrometry have been used to determine the exact nature of and relationship between these two transformations. In both materials, low dose, room temperature implantation produces spherical voids yet the material remains crystalline. With increasing implant dose, the porous layer eventually evolves into a network of straight rods 15nm in diameter. We suggest the porosity arises from preferential clustering of interstitials into extended defects and vacancies agglomerating to form voids.
  • Thumbnail Image
    Item
    Structural characterization of ion implanted Au nanocrystals using synchrotron-based analytical techniques
    (Australian Institute of Physics, 2005-01-31) Kluth, P; Johannessen, B; Glover, CJ; Foran, GJ; Kluth, SM; Ridgway, MC
    Synchrotron based analytical techniques including extended x-ray absorption fine structure (EXAFS) spectroscopy provide powerful tools for structural characterization of nanocrystalline materials. Combining these techniques with conventional analytical methods such as x-ray diffraction and transmission electron microscopy we have investigated Au nanocrystals formed in thin SiO2 using ion implantation. Furthermore, we have studied their structural evolution following ion irradiation. Non-irradiated nanocrystals show a significant bondlength contraction, essentially retaining the facecentred-cubic structure present in bulk material[1]. In contrast to bulk elemental metals, which cannot be rendered amorphous by ion irradiation, irradiated nanocrystals exhibit a significant structural change consistent with amorphous material.