Magnetic properties and atomic structure of La(2/3)Ca(1/3)MnO(3)-YBa(2)Cu(3)O(7) heterointerfaces

A heterostructure comprised of a 2.7 nm (7 unit-cell) thick layer of the metallic ferromagnet La(2/3)Ca(1/3)MnO(3) and two 50 nm thick layers of the high-temperature superconductor YBa(2)Cu(3)O(7) epitaxially grown on (100) SrTiO3 by pulsed-laser deposition was characterized by magnetization measurements and spherical-aberration-corrected high-resolution transmission electron microscopy (HRTEM). The saturation magnetization is about half of that in bulk La(2/3)Ca(1/3)MnO(3). A massive reduction of the magnetization previously inferred from sputter-deposited La(2/3)Ca(1/3)MnO(3)-YBa(2)Cu(3)O(7) heterostructures can be ruled out. HRTEM image analysis, combined with image simulation and a focus series reconstruction, revealed atomically sharp epitaxial structures with stacking sequences -(La,Ca)O-CuO2- and -BaO-MnO- at the top and bottom interface.