Soft X-ray resonant scattering study of single-crystal LaSr${}_2$Mn${}_2$O${}_7$

Abstract

Soft X-ray resonant scattering studies at the Mn $L_{\text{II, III}}$- and the La $M_{\text{IV, V}}$- edges of single-crystal LaSr${}_2$Mn${}_2$O${}_7$ are reported. At low temperatures, below $T_{\text{N}}\approx 160$ K, energy scans with a fixed momentum transfer at the \emph{A}-type antiferromagnetic (0 0 1) reflection around the Mn $L_{\text{II, III}}$-edges with incident linear $\sigma$ and $\pi$ polarizations show strong resonant enhancements. The splitting of the energy spectra around the Mn $L_{\text{II, III}}$-edges may indicate the presence of a mixed valence state, e.g., Mn${}^{3+}$/Mn${}^{4+}$. The relative intensities of the resonance and the clear shoulder-feature as well as the strong incident $\sigma$ and $\pi$ polarization dependences strongly indicate its complex electronic origin. Unexpected enhancement of the charge Bragg (0 0 2) reflection at the La $M_{\text{IV, V}}$-edges with $\sigma$ polarization has been observed up to 300 K, with an anomaly appearing around the orbital-ordering transition temperature, $T_{\text{OO}}\approx 220$ K, suggesting a strong coupling (competition) between them.

Accepted by European Physical Journal B

References in corpus (3)

• Soft x-ray resonant diffraction study of magnetic and orbital correlations in a manganite near half-doping
• Resonant X-ray Scattering in Manganites - Study of Orbital Degree of Freedom -
• A Resonant X-ray Scattering Study of Octahedral Tilt Ordering in LaMnO${}_3$ and Pr${}_{1-x}$Ca${}_x$MnO${}_3$