Interfacial electronic and magnetic properties of a Y0.6Pr0.4Ba2Cu3O7/La2/3Ca1/3MnO3superlattice

Abstract

Resonant soft x-ray absorption spectroscopy and diffuse neutron scattering were used to study the interfacial properties of Y${}_{0.6}$Pr${}_{0.4}$Ba${}_{2}$Cu${}_{3}$O${}_{7}$/La${}_{2/3}$Ca${}_{1/2}$MnO${}_{3}$ superlattices. Dramatic changes from the bulk in the spectral line shape, energy position, and linear-polarization dependence of the Cu L${}_{3}$-edge reveal a striking interfacial modification. The similarities to the case without Pr substitution confirm the strongly hybridized covalent Cu-O-Mn bond as the underlying driving mechanism. On the other hand, relative differences, including reduced charge transfer and interfacial orbital reconstruction, are observed and attributed to raising of the Fermi level of the cuprate layer with Pr substitution. Neutron reflectometry reveals an oscillatory behavior in the rapidly increasing diffuse scattering with decreasing temperature. Temperature- and field-dependent measurements indicate that the origin is associated with the buckling caused by the structural phase transition of the SrTiO${}_{3}$ substrate rather than the superconducting or magnetic transition.