High-resolution hard x-ray photoemission investigation of La2−2xSr1+2xMn2O7 (0.30<=x<0.50): Microscopic phase separation and surface electronic structure of a bilayer colossal magnetoresistance manganite

Photoemission data taken with hard x-ray radiation on cleaved single crystals of the bilayered, colossal magnetoresistant manganite La2−2xSr1+2xMn2O7 (LSMO) with 0.30<=x<0.50 are presented. Making use of the increased bulk sensitivity upon hard x-ray excitation it is shown that the core-level footprint of the electronic structure of the LSMO cleavage surface is identical to that of the bulk. Furthermore, by comparing the core-level shift of the different elements as a function of doping level x, it is shown that microscopic phase separation is unlikely to occur for this particular manganite well above the Curie temperature.