Swift heavy ion irradiation of GaSb: From ion tracks to nanoporous networks

Abstract

Ion track formation, amorphization, and the formation of porosity in crystalline GaSb induced by 185 MeV 197Au swift heavy ion irradiation is investigated as a function of fluence and irradiation angle relative to the surface normal. Rutherford backscattering spectrometry in channeling configuration and small-angle x-ray scattering reveal an ion track radius between 3 and 5 nm. The observed pore morphology and saturation swelling of GaSb films shows a strong irradiation angle dependence. Raman spectroscopy and scanning electron microscopy show that the ion tracks act as a source of strain in the material, leading to macroscopic plastic flow at high fluences and off-normal irradiation. The results are consistent with the ion hammering model for glasses. Furthermore, wide-angle x-ray scattering reveals the formation of nanocrystallites inside otherwise amorphous GaSb after the onset of porosity. Show more