Enhanced magnetism and persistent insulating state in Mn doped Sr2IrO4

The influences of Mn substitution at the Ir site of Sr2IrO4 are investigated via a comprehensive study of the variation of structural parameters, the transport and magnetic properties of the Sr2Ir1-x Mn x O4 samples. The incorporation of Mn leads to an increase of the in-plane Ir-O-Ir bond angle, while it is not sufficient to drive the Mott-insulating state to a metallic state. Interestingly, we find a coexistence of Ir4+-O2--Ir4+ super-exchange interaction and Mn3+-O2--Mn4+ double exchange interaction in x > 0.06 samples. The Mn3+-O2--Mn4+ ferromagnetic domains are isolated by the Ir4+-O2--Ir4+ antiferromagnetic areas, leading to a severely localized electronic and magnetic states. The electron hopping between the localized states dominates the conductivity of the Sr2Ir1-x Mn x O4 samples.

Automated summary

The influences of Mn substitution on the Sr site of Sr2IrO4 were investigated, focusing on the changes in structural parameters, transport, and magnetic properties. The incorporation of Mn resulted in an increase in the bond angle and a coexistence of super-exchange and double exchange interactions in certain samples. This led to severely localized electronic and magnetic states.