Depth-Resolved Magnetization and Proximity Effects in YBCO/LSMO Oxide Multilayers

Polarized neutron reflectometry (PNR) was performed on a La₀.₆₇Sr₀.₃₃MnO₃ (LSMO, ~15 nm) / YBa₂Cu₃O₇₋ₓ (YBCO, ~18 nm) multilayers at the MAGREF beamline (BL-4A), Spallation Neutron Source, ORNL. Measurements were conducted under field-cooled conditions at 0.6 T, across temperatures from 92 K to 1.5 K. In a similar system with thinner LSMO layers (~6 nm), we found magnetic dead sub-layers with zero magnetization near the interface and enhanced magnetization (M) of the main body of the LSMO layers at low temperatures. This enhancement was attributed to the emergence of spin-triplet superconducting pairs within the LSMO layers. In the current study, we aim to explore how this M enhancement is distributed in thicker LSMO layers. Our results reveal ~1 nm dead sub-layers near the interfaces, while the internal M profile of the LSMO layer body varies with temperature. The presence of these dead layers may arise from: (1) the superconducting proximity effect, where spin-singlet pairs diffuse into LSMO and suppress its magnetism; (2) interface roughness of similar thickness; or (3) the paramagnetic Meissner effect. While the enhanced M profile is attributed to the distribution of spin-triplet pairs. Detailed findings will be presented at the meeting.