Large chemical shift in Eu Lγ emission spectra

Eu is one of the most interesting lanthanides, compounds of which often exhibit remarkable optical, electrical, and magnetic properties. Therefore, it is extremely important to develop a technique for chemical state analysis. The X-ray emission spectra of Eu had not been thought to exhibit significant chemical effects. A research group led by Professor H. Hayashi (Japan Women's Univ) firstly found a large chemical shift (~5 eV) in Eu Lγ₄ emission line, depending on the valence state. They discussed the feasibility of using this as a probe for spin- and valence-selective X-ray absorption fine structure spectroscopy. For more information, see the paper, "Probe for spin- and valence-selective X-ray absorption fine structure spectroscopy: EuLγ₄ emission", H. Hayashi et al., Anal. Chem., 81, 1522 (2009).