Insight on the electronic state ofSr2IrO4 revealed by cationic substitutions

Abstract

We report the electrical resistivity, thermoelectric power and magnetization ofSr2−xLaxIrO4 (x = 0 and0.05) and Sr2Ir1−yRhyO4 (y = 0.05, 0.1 and 0.2) measured below room temperature. InSr2IrO4, electrons (La substitution) or holes (Rh substitution) can be doped, which lead to astrong decrease of the resistivity. In particular, a nearly-metallic state is realized in thecase of Rh doping. The thermoelectric power turns out to be metallic-like fory = 0.2. The presence of a gap in the electronic band structure is robust against these substitutions.From various experimental data, similarities with the 3D charge density wave compound,BaBiO3, are suggested. Nevertheless, rather than a charge density wave, our scenario implies thepresence of a spin density wave.