Work

Resonant soft x-ray powder diffraction study to determine the orbital ordering in A-site-ordered SmBaMn2O6

Year: 2008

Type: article

Abstract: Soft x-ray resonant powder diffraction has been performed at the Mn ${L}_{2,3}$ edges of A-site-ordered ${\mathrm{SmBaMn}}_{2}{\mathrm{O}}_{6}$. The energy and polarization dependences of the (1/4 1/4 0) reflection provide direct evidence for a $({x}^{2}\ensuremath{-}{z}^{2})∕({y}^{2}\ensuremath{-}{z}^{2})$-type orbital ordering in contrast to single-layer manganite. The temperature dependence of the reflection indicates an orbital reorientation transition at $\ensuremath{\approx}210\phantom{\rule{0.3em}{0ex}}\mathrm{K}$, below which the charge- and orbital-ordered ${\mathrm{MnO}}_{2}$ sheets show AAAA-type of stacking. The concurring reduction of the ferromagnetic superexchange correlations leads to further charge localization.

Source: Physical Review B

DOI: 10.1103/physrevb.77.060402