Dirac semimetal strontium iridate thin films with strong spin-orbit interaction for magnetic heterostructures

Abstract

The structural crystal features, electron transport and magnetotransport of the epitaxial strontium iridate (SrIrO$_3$) and iridate/manganite SrIrO$_3$/La$_{0.7}$Sr$_{0.3}$MnO$_3$ heterostructure have been investigated. The influence of epitaxial strain relaxation caused by the lattice mismatch between SrIrO$_3$ films and five substrates: SrTiO$_3$, NdGaO$_3$, (LaAlO$_3$)$_{0.3}$(Sr$_2$TaAlO$_6$)$_{0.7}$, LaAlO$_3$, and Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$-PbTiO$_3$ on electron and magnetic transport has been observed. A pronounced impact of strong spin-orbit interaction on characteristics of SrIrO$_3$ films has been revealed by means of X-ray photoelectron spectroscopy, magnetoresistance and Hall-resistance measurements at temperatures T = 2-300 K. These findings highlight the tunability of spin-orbit-driven transport phenomena in strain-controlled SrIrO$_3$-based epitaxial systems, relevant for future spintronic oxide heterostructures. The contribution of Kondo scattering on temperature dependence of SrIrO$_3$ films resistance was observed.