Evolution of competing magnetic order in the Jeff=1/2 insulating state of Sr2Ir1-xRuxO4

TL;DR

This study explores how magnetic structures in Sr2Ir1-xRuxO4 evolve with Ru doping, revealing a spin flop transition and coexistence of magnetic phases without changing the Jeff=1/2 ground state, offering insights into spin-orbit coupled insulators.

Contribution

It provides detailed experimental evidence of magnetic phase evolution and coexistence in Sr2Ir1-xRuxO4, highlighting the effects of Ru doping on magnetic order and insulating behavior.

Findings

Magnetic structures transition from ab-plane to c-axis with doping.

Magnetic phase coexistence occurs for x<0.3.

Jeff=1/2 ground state remains unchanged despite doping.

Abstract

We investigate the magnetic properties of the series Sr2Ir1-xRuxO4 with neutron, resonant x-ray and magnetization measurements. The results indicate an evolution and coexistence of magnetic structures via a spin flop transition from ab-plane to c-axis collinear order as the 5d Ir4+ ions are replaced with an increasing concentration of 4d Ru4+ ions. The magnetic structures within the ordered regime of the phase diagram (x<0.3) are reported. Despite the changes in magnetic structure no alteration of the Jeff=1/2 ground state is observed. The behavior of Sr2Ir1-xRuxO4 is consistent with electronic phase separation and diverges from a standard scenario of hole doping. The role of lattice alterations with doping on the magnetic and insulating behavior is considered. The results presented here provide insight into the magnetic insulating states in strong spin-orbit coupled materials and the role perturbations play in altering the behavior.