Magnetism at an iridate/manganite interface: Influence of strong spin-orbit interaction
G. A. Ovsyannikov, T. A. Shaikhulov, Konstantin Stankevich, Yu. N. Khaydukov, Nikolay Andreev
Abstract
A comprehensive study of electron and magnetic properties and spin transport in the epitaxial manganite/iridate heterostructure was carried out by using of the x-ray, dc resistance measurements, ferromagnetic resonance at microwaves, polarized neutron reflectivity, and spin-current transport. Epitaxial growth of the heterostructure proceeded according to the ``cube-to-cube'' mechanism with a small lattice turn. The dc current measurement indicates the presence of a conduction channel at the iridate/manganite interface due to the charge leak from iridate making it hole doped, while the manganite side can be doped by electron. This is confirmed by the first-principles calculations based on density-functional theory [S. Bhowal and S. Satpathy, AIP Conf. Proc. 2005, 020007 (2018)], which showed a charge transfer at the interface from the half-filled spin-orbit entangled ${J}_{\mathrm{eff}}=1/2$ state of the iridate to the empty ${e}^{\ensuremath{\uparrow}g}$ states of manganite. The neutron-scattering data show the turn of magnetization vector of the heterostructure by ${26}^{\ensuremath{\circ}}$ towards the external field with temperature reduction down to 10 K. An additional ferromagnetic state that appears at $T<100\phantom{\rule{0.16em}{0ex}}\mathrm{K}$ indicates an emergence of ferromagnetism at the interface of the paramagnetic $\mathrm{SrIr}{\mathrm{O}}_{3}$ film and ferromagnetic manganite. We measured the dc voltage that occurs on the $\mathrm{SrIr}{\mathrm{O}}_{3}$ film due to spin pumping and anisotropic magnetoresistance in the heterostructure.