Interplay of the CE-type charge ordering and the A-type spin ordering in half-doped bilayer manganite LaSr2Mn2O7

We demonstrate that the 50% hole-doped bilayer manganite LaSr2Mn2O7 exhibits CE-type charge- and spin-ordered states below T-N,CO(A) = 210 K and below T-N(CE) similar to 145 K, respectively. However, the volume fraction of the CE-type ordering is relatively small, and the system is dominated by the A-type spin ordering. The coexistence of the two types of ordering is essential to understand the transport properties, and it can be viewed as an effective phase separation between the metallic d(x(2) - y(2)) orbital ordering and the charge-localized d(3x(2) - r(2))/d(3y(2) - r(2)) orbital ordering.