Dzyaloshinsky–Moriya Interaction Induced Anomalous g Behavior of Sr2IrO4 Probed by Electron Spin Resonance

Among the 5d transition metal iridates, Sr2IrO4, which has a layered chalcogenide structure, has received much attention due to its strong spin–orbit coupling (SOC), which produces Mott insulating states and anomalous physical behaviors. In this paper, the microscopic magnetism of Sr2IrO4is studied with electron spin resonance (ESR) measurements. The Lande factorgof the ferromagnetic resonance signal of Sr2IrO4shows anomalous behavior compared to typical ferromagnets. It gradually decreases, and the corresponding resonance fieldHrincreases, with decreasing temperature. The various physical parameters. including the saturated magnetic fieldHsderived fromM-H,Hr, ΔHpp, thegfactor and the intensityIextracted from ESR spectra, are analyzed in detail. Eventually, it is revealed that the anomalous behavior of theg-factor is induced by in-plane Dzyaloshinsky–Moriya interaction (DMI) rather than the SOC effect.