Magnetotransport properties of Ca0.8La0.2IrO3 epitaxial films

Abstract

We fabricated high-quality epitaxial Ca0.8La0.2IrO3 (CLIO) films on SrTiO3 (STO), (LaAlO3)0.3(Sr2AlTaO6)0.7 (LSAT) and NdGaO3 (NGO) substrates by pulsed laser deposition, and systematically studied their transport properties. All samples showed insulating behavior, but the resistivity of CLIO/NGO film showed relatively weak temperature dependence and can be regarded as a poor metallic behavior. The carrier transport in all the samples were dominated by the Mott-type variable range hopping. The magnetoresistance of CLIO/NGO showed a value about 6%, larger than that of CLIO/STO and CLIO/LSAT, while the CLIO/STO sample showed very large magnetic moment and small coercive field. These findings indicate that mechanical strain can be a useful route to explore the unusual physics of iridates with strong spin-orbit coupling.