Spin resolved photoelectron spectroscopy of [Mn6IIICrIII]3+ single-molecule magnets and of manganese compounds as reference layers

Properties of the manganese-based single-molecule magnet [MnIII6CrIII]3+ are studied. It contains six MnIII ions arranged in two bowl-shaped trinuclear triplesalen building blocks linked by a hexacyanochromate and exhibits a large spin ground state of St = 21/2. The dominant structures in the electron emission spectra of [MnIII6CrIII]3+ resonantly excited at the L3-edge are the L3M2,3M2,3, L3M2,3V and L3VV Auger emission groups following the decay of the primary p3/2 core hole state. Significant differences of the Auger spectra from intact and degraded [MnIII6CrIII]3+ show up. First measurements of the electron spin polarization in the L3M2,3V and L3VV Auger emission peaks from the manganese constituents in [MnIII6CrIII]3+ resonantly excited at the L3-edge near 640 eV by circularly polarized synchrotron radiation are reported. In addition spin resolved Auger electron spectra of the reference substances MnO, Mn2O3 and MnII(acetate)2·4H2O are given. The applicability of spin resolved electron spectroscopy for characterizing magnetic states of constituent atoms compared to magnetic circular dichroism (MCD) is verified: the spin polarization obtained from MnII(acetate)2·4H2O at room temperature in the paramagnetic state compares to the MCD asymmetry revealed for a star-shaped molecule with a Mn4IIO6 core at 5 K in an external magnetic field of 5 T.