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Soft x-ray resonant diffraction study of magnetic and orbital correlations in a manganite near half-doping

K. J. Thomas·J. P. Hill·Y-J. Kim·S. Grenier·P. Abbamonte·L. Venema·A. Rusydi·Y. Tomioka·Y. Tokura·D. F. McMorrow·M. van Veenendaal
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Abstract

We have utilized the resonant x-ray diffraction technique at the Mn L-edge in order to directly compare magnetic and orbital correlations in the Mn sub-lattice of Pr0.6Ca0.4MnO3. The resonant line shape is measured below T_OO ~ 240 K at the orbital ordering wave vector (0,1/2,0), and below T_N ~ 175 K at the antiferromagnetic wave vector (1/2,0,0). Comparing the width of the super-lattice peaks at the two wavevectors, we find that the correlation length of the magnetism exceeds that of the orbital order by nearly a factor of two. Furthermore, we observe a large (~ 3 eV) shift in spectral weight between the magnetic and orbital line shapes, which cannot be explained within the classic Goodenough picture of a charge-ordered ground state. To explain the large shift, we calculate the resonant line shapes for orbital and magnetic diffraction based on a relaxed charge-ordered model.

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K. J. Thomas, J. P. Hill, Y-J. Kim, S. Grenier, P. Abbamonte, L. Venema, A. Rusydi, Y. Tomioka, Y. Tokura, D. F. McMorrow, M. van Veenendaal. 2003-11-24. Soft x-ray resonant diffraction study of magnetic and orbital correlations in a manganite near half-doping. https://doi.org/10.1103/physrevlett.92.237204

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