Electronic structure of Cr silicides and Si-Cr interface reactions

We present synchrotron radiation photoemission studies of bulk Cr${\mathrm{Si}}_2$ and silicide phases grown on Si by thermal processing of the Si-Cr interface. Experiment shows that Si-Cr interface formation at room temperature results in reacted phases that differ from both bulk Cr${\mathrm{Si}}_2$ and in situ—grown Si-rich Cr${\mathrm{Si}}_2$. Extended—Hückel-theory linear combination of atomic orbitals calculations of the density of states of ${\mathrm{Cr}}_3$Si, CrSi, and Cr${\mathrm{Si}}_2$ show that Si—Cr bond formation involves Si $p$ and Cr $d$ states with minimal charge transfer.