Suppression of interface-induced electronic phase separation in all-manganite multilayers by preservation of the Mn-O chain network

All-manganite multilayers of La2/3D1/3MnO3 with D=Ca,Sr (LCMO/LSMO) were prepared in situ by off-axis pulsed laser deposition and investigated for their resistive and magnetic properties. The multilayers show a high structural quality as evidenced by x-ray diffraction and Rutherford backscattering experiments. Transport and magnetization experiments show the suppression of resistivity increase and loss in magnetic moment commonly encountered in very thin manganite films and multilayers with insulator partial layers as a consequence of an interface-induced electronic phase separation. Comparison of both types of film structures allows for the conclusion that the breakup of Mn-O chains leads to a modified Mn4+/Mn3+ ratio at interfaces which is responsible for the extrinsic electronic phase separation. We propose to explain the enhancement of LCMO resistivity yet observed by mechanical stress induced in the LCMO layers by the lattice mismatch with LSMO.