Matrix-isolation study of FeCo molecules

Rare-gas matrix-isolation techniques have been used in conjunction with Mössbauer spectroscopy to study bimetallic molecules of FeCo. The electronic ground state for the heteronuclear diatomic molecule FeCo was determined from symmetry considerations as ${}_{}{}^6{}_{}{}^{}\Sigma$. It was also determined that the coupling between the atoms was ferromagnetic. In addition the trimeric species ${\mathrm{Fe}}_2$Co and Fe${\mathrm{Co}}_2$ were identified and their Mössbauer parameters determined. Higher multimers of iron-cobalt were also studied and magnetic hyperfine splitting was observed with fields ranging between 276 and 345 kOe. This last value was obtained for 25 at.% metal in solid argon with a cobalt to iron ratio of one; at this concentration long-range order is already present.