In situ extended X-ray absorption fine structure study on the local structure around gallium in liquid silicon

The local structure around gallium of 0.5, 1 and 5 at.% in liquid silicon at 1440degC has been investigated by the extended X-ray absorption fine structure (EXAFS). The amplitude of EXAFS oscillations is distinct for the very dilute case of 0.5 at.% gallium. The EXAFS analysis shows that the structural parameters of Ga-Si pairs change from 2.8 atoms at a distance of 2.36 A to 2.1 atoms at a distance of 2.43 A with increasing gallium content in liquid silicon. These results suggest that a certain local structure around gallium in liquid silicon is formed at low gallium content and that this structural feature disappears with increasing gallium content. (author)