Magnetism at an iridate/manganite interface: Influence of strong spin-orbit interaction

Abstract

The complex investigation of dc transport and magnetic properties of the epitaxial manganite/iridate heterostructure was carried out by mean of X-ray (XRD), dc resistance measurements, ferromagnetic resonance (FMR) and polarized neutron reflectivity (PNR). Epitaxial growth of the heterostructure proceeded according to the cube-to-cube mechanism with the small lattice turn. The dc measurement indicates the presence of a conduction channel at the iridate/manganite interface due to the charge leakage from iridate that makes it hole doped, while the manganite side becomes electron doped. This is confirmed by the first principles calculations based on density functional theory [Sayantika Bhowal, and Sashi Satpathy AIP Conference Proceedings 2005, 020007 (2018)] that show the charge transfer at the interface from the half-filled spin-orbit entangled Jeff = 1/2 state of the iridate to the empty e states of manganite. The neutron scattering data show the turn of magnetization vector of the heterostructure (mainly manganite) on 26 degree closer to the external field with reducing temperature down to 10K. Additional ferromagnetic state appearing at T<100K indicate on emergence of ferromagnetism in the thin (10 nm) paramagnetic SIO film close to the interface. We have measured the dc voltage aroused on the SIO film caused by spin pumping and the anisotropic magnetoresistance in the heterostructure.