  At a superconductor-ferromagnet (S/F) interface, the F layer can introduce a
magnetic exchange field within the S layer, which acts to locally spin split
the superconducting density of states. The effect of magnetic exchange fields
on superconductivity has been thoroughly explored at S-ferromagnet insulator
(S/FI) interfaces for isotropic s-wave S and a thickness that is smaller than
the superconducting coherence length. Here we report a magnetic exchange field
effect at an all-oxide S/FI interface involving the anisotropic d-wave high
temperature superconductor praseodymium cerium copper oxide (PCCO) and the FI
praseodymium calcium manganese oxide (PCMO). The magnetic exchange field in
PCCO, detected via magnetotransport measurements through the superconducting
transition, is localized to the PCCO/PCMO interface with an average magnitude
that depends on the presence or absence of magnetic domain walls in PCMO. The
results are promising for the development of all-oxide superconducting
spintronic devices involving unconventional pairing and high temperature
superconductors.
