We have experimentally investigated the charge density distribution and the electrostatic potential for a charge-ordering doped manganite, ${\mathrm{Nd}}_{1∕2}{\mathrm{Sr}}_{1∕2}{\mathrm{MnO}}_3$. In the charge-ordered state, we observed a zigzag pattern of the charge density within the (010) plane. Judging from the ${\mathrm{MnO}}_6$ distortion, we ascribed the pattern to the bonding electron in the $p_{x\left(y\right)}-d_{x^2-y^2}$ hybridized state, not to the so-called $d_{3x^2-r^2}∕d_{3y^2-r^2}$ orbital ordering. We further calculated the electrostatic potential $U\left(r\right)$ from the charge density and the atomic positions, which clearly indicates the checkerboard-type charge disproportionation within the (010) plane.

• Received 4 January 2008

DOI:https://doi.org/10.1103/PhysRevB.77.081101