Investigation of highly ferromagnetic Mn2Ge4 and Mn2Ge5 clusters via photoelectron spectroscopy and theoretical calculations

We investigate the structures and properties of Mn2Ge4-/0 and Mn2Ge5-/0 by anion photoelectron spectroscopy and theoretical calculations. The vertical detachment energies (VDEs) of Mn2Ge4- and Mn2Ge5- are measured to be 2.69 eV and 2.49 eV, respectively. It is found that neutral Mn2Ge4 has an approximate quadrilateral bipyramidal structure with C-2v symmetry and B-11(2) electronic state. Neutral Mn2Ge5 has a pentagonal bipyramidal structure with C-2v symmetry and B-11(2) electronic state. The 4s-based molecular orbitals of the Mn atoms participate in the chemical bonding with the Ge-4 and Ge-5 fragments in Mn2Ge4 and Mn2Ge5. In Mn2Ge4, the two Mn atoms interact with the Ge-4 moiety via four GeGeMn 3c-2e sigma bonds. In Mn2Ge5, the two Mn atoms interact with the Ge-5 moiety via one MnGeMn 3c-2e sigma bond and four GeMnGe 3c-2e sigma bonds. The analysis of magnetic properties reveals that both Mn2Ge4 and Mn2Ge5 exhibit highly ferromagnetic characteristics with a magnetic moment of 10 mu(B) which mainly originated from the Mn atoms. These double Mn atom doped germanium clusters may provide new opportunities to design novel spintronic devices featuring high magnetic moments.

Automated summary

The structures and properties of Mn2Ge4-/0 and Mn2Ge5-/0 were investigated using anion photoelectron spectroscopy and theoretical calculations. It was found that both clusters have specific molecular structures and electronic states, exhibiting highly ferromagnetic characteristics.