Swift heavy ion irradiation of GaSb: from ion tracks to nano-porous networks

TL;DR

This study explores how swift heavy ion irradiation creates ion tracks, porosity, and nano-crystallites in GaSb, revealing angle-dependent effects and strain-induced plastic flow, advancing understanding of ion-induced nanostructuring.

Contribution

It provides detailed insights into ion track formation, porosity, and nano-crystallite development in GaSb under heavy ion irradiation, highlighting the influence of irradiation angle and fluence.

Findings

Ion track radius between 3-5 nm.

Porosity and swelling depend on irradiation angle.

Nano-crystallites form inside amorphous GaSb after porosity onset.

Abstract

Ion track formation, amorphisation, and the formation of porosity in crystalline GaSb induced by 185 MeV $^{197}$Au swift heavy ion irradiation is investigated as a function of fluence and irradiation angle relative to the surface normal. RBS/C and SAXS reveal an ion track radius between 3 nm 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 nano crystallites inside otherwise amorphous GaSb after the onset of porosity.