Structural changes of silicon upon high-energy milling investigated by Raman spectroscopy

This study showed pronounced changes in the Raman scattering of silicon powder during high-energy ball milling. The powders were milled for 1-18 h in a steel ball mill in argon. The approximate pressure imposed on particles was 2 GPa. The spectra of the as-milled powders were compared with the initial silicon. It was found from the Raman peak position shifts that milling generated strains in the silicon lattice, bringing about a transformation of cubic silicon to tetragonal silicon and amorphization. The relative amount of new phases was determined from the area under the measured Raman peaks