Beta-induced decrease in the content of the Si-II, Si-XII, Si-III, and $\alpha$-Si silicon phases formed under an indenter

Volumes of the metastable Si-II, Si-XII, Si-III, and $\alpha$-Si silicon phases in a locally deformed (Berkovich pyramid) region of unirradiated and beforehand irradiated Si single crystals are quantitatively estimated. Experimental data obtained by Raman spectroscopy and in situ detection of Si-I $\to$ Si-II silicon phase transformations under an indenter are used to calculate the volumes. The preliminary irradiation of silicon by $\beta$ particles from a $^{90}$Sr–$^{90}$Y source (fluence $F$ = 3.24 $\times$ 10$^{10}$ cm$^{-2}$, intensity $I$ = 1.8 $\times$ 10$^5$ cm$^{-2}$ s$^{-1}$) reduces the volume of these phases by a factor of more than 1.5.