Electronic structure study of the "ferric star" single molecule magnet

New materials based on metal-oxygen clusters are promising stages of development in nano/micro electronic applications that can lead to the emergence of a new technology. Molecules containing several transition metal ions can exhibit properties similar to nanoscale magnetic particles. Our approach in this field is the study of the electronic structure of these materials by means of spectroscopic investigations in combination with theoretical calculations. The electronic structure of magnetic molecules of the type [Fe(FeL2)3]*4CHCl3 where L=CH3N(CH2CH2O)^2-_2 NO2 has been studied using X-ray photoelectron spectroscopy, soft X-ray emission spectroscopy as well as theoretical density-functional-based methods. Experimental XPS results are in a good agreement to the calculated tDOS, also the partial DOS agrees very well with the XES results. The Fe core level spectra indicate that Fe is in the Fe 2+ state, which is in a good agreement with the calculated magnetic moment of 4 muB/f.u. The neighbouring atoms primarily oxygen and nitrogen exhibit a magnetic polarisation yielding effective spin S=5/2 per iron atom. Due to antiparallel orientation of the magnetic moments of the central Fe ion relatively to three peripheric Fe, the total resulting spin per molecule in the ground state amounts to S=5.