1203.1865 (M. Schmitt et al.)

Tuning the Eu valence in EuPd_3B_x: pressure versus valence electron
count - a combined computational and experimental study    [PDF]

M. Schmitt, R. Gumeniuk, A. Trapananti, G. Aquilanti, C. Strohm, K. Meier, U. Schwarz, M. Hanfland, W. Schnelle, A. Leithe-Jasper, H. Rosner

In a joint theoretical and experimental study we investigate the pressure dependence of the Eu valence in EuPd_3B_x (0 <= x <= 1). Density functional band structure calculations are combined with x-ray absorption and x-ray diffraction measurements under hydrostatic pressures up to 30 GPa. It is observed that the heterogenous mixed-valence state of Eu in EuPd_3B_x (x >= 0.2) can be suppressed partially in this pressure range. From the complementary measurements we conclude that the valence change in EuPd_3B_x is mainly driven by the number of additional valence electrons due to the insertion of boron, whereas the volume change is a secondary effect. A similar valence change of Eu in Eu_{1-x}La_xPd_3 is predicted for x >= 0.4, in line with the suggested electron count scenario.

View original: http://arxiv.org/abs/1203.1865