Abstract:
Epitaxial strontium iridate (SrIrO$_3$) thin films were fabricated by RF magnetron sputtering on single-crystal substrates: (110)NdGaO$_3$, (001)SrTiO$_3$, (001)(LaAlO$_3$)$_{0.3}$(Sr$_2$TaAlO$_6$)$_{0.7}$ (LSAT) and (110)Pb(Mg$_{1/3}$Nb$_{2/3}$)O$_3$-PbTiO$_3$ (PMN-PT). X-ray diffraction techniques were used to investigate structural characteristics and the effect of strain in thin films induced by lattice parameter mismatch between the film and substrate. Analysis of diffraction data revealed changes in the unit cell volume compared to the orthorhombic phase of SrIrO$_3$ crystal in pseudocubic representation. Electronic transport parameters of SrIrO$_3$ thin films exhibit significant dependence on the substrate and deposition conditions. Temperature-dependent resistance analysis revealed the effect of magnetic impurity scattering, attributed to oxygen vacancies, on the electronic transport properties of the films. X-ray photoelectron spectroscopy measurements determined the spin-orbit splitting energy for the Ir 4$f$ core level, which varies from 2.99 eV for the SrIrO$_3$ film on (001)SrTiO$_3$ to 3.10 eV for the SrIrO$_3$ film on (110)PMN-PT, correlating with oxygen vacancy concentration, structural perfection, and stoichiometry.
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