Site-Specific Valence Band Photoemission from La1/2Sr3/2MnO4 Using X-Ray Standing Waves
Abstract
By manipulating the position of the X-ray standing-wave field which is formed from the superposition of incident and reflected X-ray beams within the vicinity of a crystal Bragg reflection, we selectively examine the intensities of valence photoelectrons emitted from different parts of the unit cell of La1/2Sr3/2MnO4. For the (114) and (204) reflections, we measure enhanced emission at the higher binding energy part of the valence band when the standing-wave field intensity is maximized on the Mn atoms, indicating a higher density of Mn valence states. Similarly, the lower binding energy part of the valence band has more valence state emission from O, La, and Sr. The (116) and (213) reflections separate the O atoms in the Mn-O planes from those outside them. The measured valence band spectra lineshape is unchanged with wavefield position, suggesting that O 2p emission is weak in the valence band near 4 keV photon energy, as also was seen in our experiments on NiO.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 2001
- Bibcode:
- 2001APS..MARN24010N