Dresden 2006 – wissenschaftliches Programm
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TT: Tiefe Temperaturen
TT 25: Correlated Electrons - Poster Session
TT 25.88: Poster
Mittwoch, 29. März 2006, 14:30–18:30, P1
Coupling between spin and orbital order in La0.5Sr1.5MnO4? — •C. F. Chang1, M. Buchholz1, C. Schüßler-Langeheine1, M. Benomar1, E. Schierle2, E. Weschke2, G. Kaindl2, M. Braden1, and L. H. Tjeng1 — 1II. Physikalisches Institut, Universität zu Köln, Zülpicher Str. 77, 50937 Köln, Germany — 2Institut für Experimentalphysik, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany
In La0.5Sr1.5MnO4 spin, orbital and charge order occurs at low temperatures. Resonant soft x-ray diffraction data show an increase in intensity for the superstructure peak related to orbital order below TN, when the antiferromagnetic spin order sets in [1]. While this results indicates a coupling between antiferromagnetic order and orbital order, a recent study using polarization analysis assigned the gain in intensity to a magnetic scattering contribution to the orbital order peak intensity below TN [2]. We studied the k-space around the orbital order peak and found a broad diffuse background of magnetic origin, which has considerable intensity at the position of the orbital order peak. The relative intensity of this background varies for different positions on the sample. Sample positions without magnetic background allowed us to study the resonance behavior of the orbital order peak above and below TN.
[1] S. B. Wilkins et al., Phys. Rev. Lett. 91, 167205 (2003)
[2] U. Staub et al., Phys. Rev. B 71, 214421 (2005)