Probing ground states in intermediate valence Yb coordination systems

Compounds in which integer valence states cannot be assigned, i.e. are intermediate valence, have often multiconfigurational ground states with resultant exotic magnetic properties. Such compounds are dominated by ytterbium bipyridine molecular complexes. We have now incorporated “intermediate valence” units into extended 1D chains, expected to host novel conductivity and magnetism, but for which structural analysis and magnetic measurements alone cannot confirm the presence of intermediate valency. XANES measurements are the single best method for elucidation of the valency in such compounds. XMCD measurements, however, will allow for direct measurement of not only the 4f occupation, but the element-specific magnetization, allowing elucidation of the full ground state electronic configuration. We will perform the first L3-edge XMCD measurements of two reference known intermediate valence compounds, before characterizing our 1D polymeric systems by both L3-edge XANES and XMCD.