For TGbetween 567 and 570◦C and Sr/Bi ratio between 0.32–0.5,a partially modified Si is obtained, while in areas of TGmore than570◦C and Sr/Bi ratio less than 0.32, Si exhibits a flake-like unmodi-fied structure. Moreover, as can be seen, higher level of Sr modifier(higher ratio) is required to achieve modified Si with the presenceof Bi in the melt. In addition, similar results can be attained interms of depression of eutectic growth temperature (TEG). Litera-ture review suggests that a minimum eutectic depression of 6–8◦Cis essential to obtain a modified structure [21]. As can be seen fromFig. 10b, for a depression less than 3◦C the Si structure remainsunmodified