Strain induced changes of electronic properties of B-site ordered double perovskite Sr$_2$CoIrO$_6$ thin films

TL;DR

This study investigates how different strain states in epitaxially grown Sr$_2$CoIrO$_6$ thin films influence their electronic and magnetic properties, revealing strain-dependent magnetic easy axis orientation and magnetoresistance behavior.

Contribution

It demonstrates the strain-induced switching of magnetic easy axis and magnetoresistance sign in B-site ordered Sr$_2$CoIrO$_6$ thin films, using advanced characterization techniques.

Findings

Magnetic easy axis switches from in-plane to out-of-plane with strain reversal.

Magnetoresistance sign changes depending on strain state.

Strain affects magnetic and electronic properties significantly.

Abstract

B-site ordered thin films of double perovskite Sr$_2$CoIrO$_6$ were epitaxially grown by a metal-organic aerosol deposition technique on various substrates, actuating different strain states. X-ray diffraction, transmission electron microscopy and polarized far-field Raman spectroscopy confirm the strained epitaxial growth on all used substrates. Polarization dependent Co $L_{2,3}$ X-ray absorption spectroscopy reveals a change of the magnetic easy axis of the antiferromagnetically ordered (high-spin) Co$^{3+}$ sublattice within the strain series. By reversing the applied strain direction from tensile to compressive, the easy axis changes abruptly from in-plane to out-of-plane orientation. The low-temperature magnetoresistance changes its sign respectively and is described by a combination of weak anti-localization and anisotropic magnetoresistance effects.