title: Pressure-induced electronic mixing and enhancement of ferromagnetic ordering in EuX (X=Te, Se, S, O) magnetic semiconductors.
abstract: The pressure- and anion-dependent electronic structure of EuX (X=Te, Se, S, O) monochalcogenides is probed with element- and orbital-specific x-ray absorption spectroscopy in a diamond anvil cell. An isotropic lattice contraction enhances the ferromagnetic ordering temperature by inducing mixing of Eu 4f and 5d electronic orbitals. Anion substitution (Te-->O) enhances competing exchange pathways through spin-polarized anion p states, counteracting the effect of the concomitant lattice contraction. The results have strong implications for efforts aimed at enhancing FM exchange interactions in thin films through interfacial strain or chemical substitutions.
authors.affiliation: Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439, USA.
authors.forename: Narcizo M
authors.initials: NM
authors.lastname: Souza-Neto
authors.forename: Daniel
authors.initials: D
authors.lastname: Haskel
authors.forename: Yuan-Chieh
authors.initials: YC
authors.lastname: Tseng
authors.forename: Gerard
authors.initials: G
authors.lastname: Lapertot