Pressure induced valence change of Eu in EuFe < inf > 2 < /inf > As < inf > 2 < /inf > at low temperature and high pressures probed by resonant inelastic x-ray scattering

Abstract

The effect of pressure on the valence state of Eu in EuFe 2As2 has been investigated at high pressures up to 43 GPa at 10 K using resonant inelastic x-ray scattering and x-ray absorption spectroscopy using partial fluorescence yield. Two distinct density functional approaches have been used to complement the experiments. Our experimental results show that the Eu valence increases from a divalent state to a nearly trivalent state under application of pressure in consistence with theoretical simulations. Furthermore, our calculations show that the Eu magnetic moments prevail at high pressure up to 45 GPa. © 2014 AIP Publishing LLC.