3.Below is a selected area electron diffraction pattern from a polycrystalline region,taken from a cast steel block.There is concern that silicon may have been introduced into the casting as an impurity. Solve the pattern and index the rings.Is there any evidence for the presence of crystalline Si? Fe+Si Si Fe Si da=0.3135 nm a-Fe (bcc a=0.2866 nm)d(o)=0.203 nm3. Below is a selected area electron diffraction pattern from a polycrystalline region, taken from a cast steel block. There is concern that silicon may have been introduced into the casting as an impurity. Solve the pattern and index the rings. Is there any evidence for the presence of crystalline Si?