Correlated momentum, charge and magnetization density in the kagome staircase system Co3V2O8

• Applicant: Professor Dr.-Ing. Hartmut Fueß
• Subject Area: Analytical Chemistry
• Term: from 2009 to 2012
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 131747701

The simultaneous analysis of the momentum, charge and magnetization density is an excellent procedure for gaining insights into the electronic structure of magnetically ordered materials like the 3d transition metal oxide Co3V2O8. In this context different methods have already been employed in order to cover two of the fundamental density distributions: The density distribution of unpaired electrons has been investigated in real space by the polarized neutron diffraction technique and in momentum space by magnetic Compton scattering. In addition the electron density should be deduced by short wavelength synchrotron radiation and X-ray laboratory measurements as well as convergent beam electron diffraction (CBED). The correlation of the experimental densities is a powerful tool, which permits to obtain interesting and meaningful results concerning the magnetic form factors and the element specific degree of covalency in the electronic configuration. The refinement of the 3d orbital occupation should provide a theoretical model, capable to explain the magnetic properties resulting from superexchange interactions. Furthermore, the deduction of the spin and orbital part of the magnetic moments of the involved species, which can be determined based on Xray Circular Magnetic Dichroism (XMCD) will yield the necessary information for the correct contribution of the different elements (Co, V, O) to the density distributions. The superexchange interactions should by quantized with the knowledge of the spin and orbital moments, which will contribute to the clarification of the chemical bond in the magnetically ordered oxides of the 3d transition metals.

• DFG Programme: Priority Programmes
• Subproject of: SPP 1178: Experimental Charge Density as the Key to Understand Chemical Interactions
• Participating Persons: Professor Dr. Helmut Ehrenberg; Dr. Navid Qureshi