Interplay between intrinsic and stacking-fault magnetic domains in bi-layered manganites

We present a low temperature x-ray photoemission electron microscopy study of the bi-layered manganite compound La$_{1.2}$Sr$_{1.8}$Mn$_2$O$_7$ (BL-LSMO) to investigate the influence of stacking faults, which are structurally and magnetically different from the bi-layered host [1]. In BL-LSMO, small magnetic moment persists to $T^* = 300$ K, well above the Curie temperature of 120 K ($T_C$). Our magnetic images show that 3D stacking faults are responsible for the $T^*$ transition. Furthermore, close to $T_C$, stacking faults are well coupled to the bi-layered host with latter magnetic domains controlling the spin direction of the stacking faults. Contrary to recent reports, we find that stacking faults do not seed magnetic domains in the host via an exchange spring mechanism and the intrinsic $T_C$ of the BL-LSMO is not lower than 120 K. [1] Appl. Phys. Lett. 101, 132402 (2012)