Structural, Magnetization and Spin Wave Analysis in Layered 5d Iridate Sr2IrO4

Abstract

Magnetic behavior has been studied in 5d layered compound Sr2IrO4. The material shows reasonable spin-orbit coupling effect. A canted type antiferromagnetic spin ordering induced by Dzyaloshinskii-Moriya antisymmetric interaction arising from IrO6 octahedral distortion is observed. Our structural analysis shows a rotation of IrO6 octahedra by ∼11.3° around c axis which works as precursor for (canted) weak ferromagnetic phase. Temperature dependant magnetization shows transition temperature ∼225 K and field dependent magnetization shows low moment 0.055 μB/f.u. Our spin-wave analysis of low temperature magnetization data shows very high stiffness constant ∼3365 meVÅ2, which is interesting for this low moment spin canting system.