High-pressure tuning of valence and magnetic interactions in Eu0.5Yb0.5Ga4

Pressure-induced changes in valence and magnetic ordering are observed in a Eu0.5Yb0.5Ga4 compound by means of element selective x-ray absorption spectroscopy at Eu and Yb L3 edges. Concomitant Eu and Yb valence transitions towards a 3+ state, together with an antiferromagnetic to ferromagnetic transition, are observed with applied pressures up to 30 GPa. With the support of density functional theory calculations, we argue that hybridization between (Eu/Yb)-5d and Ga orbitals regulates the valence and magnetic exchange interactions in this system.