Enhancement of Spin Mixing Conductance in La0.7Sr0.3MnO3/LaNiO3/SrRuO3 Heterostructures

Spin pumping and the effective spin‐mixing conductance in heterostructures based on magnetic oxide trilayers composed of La0.7Sr0.3MnO3 (LSMO), LaNiO3 (LNO), and SrRuO3 (SRO) are investigated. The heterostructures serve as a model system for an estimation of the effective spin‐mixing conductance at the different interfaces. The results show that by introducing a LNO interlayer between LSMO and SRO, the total effective spin‐mixing conductance increases due to the much more favorable interface of LSMO/LNO with respect to the LSMO/SRO interface. Nevertheless, the spin current into the SRO does not decrease because of the spin diffusion length of λLNO≈3.2 nm in the LNO. This value is two times higher than that of SRO. The results show the potential of using oxide interfaces to tune the effective spin‐mixing conductance in heterostructures and to bring novel functionalities into spintronics by implementing complex oxides. Oxides have a tremendous variety of properties, which can be tuned by deposition and operation conditions. Due to their crystal structure, oxides can be deposited epitaxial on each other, which results in smooth interfaces. This makes them very suitable for the investigation of interface effects, as the spin‐mixing conductance, in spintronics. Herein, the interface effects in LSMO/LNO/SRO heterostructures are investigated.