Effect of Ce doping on the structural, transport and magnetic properties of Sr2IrO4 epitaxial films

Abstract

Sr2IrO4 is predicted to be superconducting and has received extensive attention in the field of high-temperature superconducting. Bulk Sr2IrO4 can be converted to a metallic state by slight chemical doping. Here we studied the structure, morphology, transport and magnetism of (Sr1−x Ce x )2IrO4 (x= 0, 0.0125, 0.025, 0.05) epitaxial films grown on (LaAlO3)0.3(Sr2AlTaO6)0.35 substrates. Unlike the bulk Sr2IrO4 material, the doped Sr2IrO4 epitaxial film maintains a wide range of Mott variable-range hopping characteristics in transport. Meanwhile, the magnetic properties and Raman characteristic peaks of the doped films become weakened, and the degree of weakening is proportional to the doping concentration. These observations can be attributed to the localization caused by disorder after Ce doping and the presence of structural defects. The epitaxial strain may result in important differences between Sr2IrO4 epitaxial thin films and bulk single crystals.