Spin mixing conductance and spin magnetoresistance of iridate/manganite interface

TL;DR

This study investigates spin current, spin mixing conductance, and magnetoresistance in SrIrO3/La0.7Sr0.3MnO3 heterostructures, revealing significant spin-orbit effects and a high spin Hall angle through experimental measurements.

Contribution

First experimental analysis of spin mixing conductance and spin magnetoresistance in iridate/manganite heterostructures with strong spin-orbit interaction.

Findings

Both real and imaginary parts of spin mixing conductance are significant.

The spin Hall angle exceeds that of Pt/La0.7Sr0.3MnO3 interface.

Estimated spin current constitutes one-third of the total response.

Abstract

We present results on experimental studies of spin current, measured under spin pumping at ferromag-netic resonance in wide frequency band 2-20 GHz for SrIrO3/La0.7Sr0.3MnO3 heterostructures fabricated by RF magnetron sputtering at high temperature. The epitaxial growth of the thin film in heterostructure by a cube-on-cube mechanism was confirmed by XRD and TEM analysis. Taking into account the con-tribution of anisotropic magnetoresistance the spin current was estimated as 1/3 of the total response. We show that both real and imaginary parts of spin mixing conductance are valuable for heterostructures with strong spin-orbit interaction in SrIrO3. Imaginary part of spin mixing conductance was estimated by means of shift of ferromagnetic resonance field of La0.7Sr0.3MnO3 layer in heterostructure. The spin mag-netoresistance was evaluated from angular dependencies of magnetoresistance measured in planar Hall configuration. In order to extract the influence of anisotropic magnetoresistance a La0.7Sr0.3MnO3 film was measured as well. The spin Hall angle for heterostructure was found higher than for interface Pt/ La0.7Sr0.3MnO3.