The magnetic hyperfine interaction of iron monomers and dimers isolated in an argon matrix

Abstract

The Mössbauer effect has been used to measure the magnetic hyperfine interaction of isolated iron monomers and dimers in solid argon with an applied external magnetic field. For an applied external field of 30 kOe an internal magnetic field at the 57Fe nucleus for the iron monomer of 830±15 kOe was observed (external field included). The internal field at the 57Fe nucleus in the iron dimer is 660±5 kOe with a negative Vzz(eQVzz<0). The large internal field at the 57Fe nucleus in the iron dimer indicates that the ground state of the Fe2 molecule has a large angular momentum. Also observed was a six-line spectrum with an internal field of 442±8 kOe and isomer shift of 0.50±0.06 mm/sec. This spectrum is attributed to the presence of molecules or clusters of FeO.