X-Ray Absorption Spectroscopy in Electrical Fields?An Element-Selective Probe of Atomic Polarization
Sprache des Vortragstitels:
2016 MRS Fall Meeting and Exhibit
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X-ray absorption spectroscopy (XAS) has already proven to be a powerful experimental technique to probe the valence state and local structural properties with element specificity. Combined with the x-ray magnetic circular dichroism in magnetic fields it allows in-depth investigations on novel functional, multiconstiuent materials like doped or complex oxides. We have recently shown that this tool-box can be augmented by studying oxides using XAS in electrical fields . Upon applying a voltage across a doped oxide the XAS shifts in photon energy. This shift depends linear on the external voltage and in only present in polar samples. It is therefore the x-ray variant of the linear Stark effect. In Co-doped ZnO it was demonstrated that it enables to measure atomic polarization with element specificity since the observed shift was different for Co compared to Zn . Combined XAS in electric and magnetic field is therefore envisioned to be a powerful tool to study magneto-electric phonomena in multiferroic materials and preliminary results for magneto-electric coupling in Mn-doped SrTiO3 will be discussed.
 V. Ney et al., Phys. Rev. B 93 (2016) 035136