The magnetic and crystal structures of Sr2IrO4: A neutron diffraction study

Abstract

We report a single-crystal neutron diffraction study of the layered $\mathrm{S}{\mathrm{r}}_2\mathrm{Ir}{\mathrm{O}}_4$. This work unambiguously determines the magnetic structure of the system and reveals that the spin orientation rigidly tracks the staggered rotation of the $\mathrm{Ir}{\mathrm{O}}_6$ octahedra in $\mathrm{S}{\mathrm{r}}_2\mathrm{Ir}{\mathrm{O}}_4$. The long-range antiferromagnetic order has a canted spin configuration with an ordered moment of 0.208(3) ${\mu }_B$/Ir site within the basal plane; a detailed examination of the spin canting yields 0.202(3) and 0.049(2) ${\mu }_B$/site for the a axis and the b axis, respectively. It is intriguing that forbidden nuclear reflections of space group $I{4}_1/acd$ are also observed in a wide temperature range from 4 K to 600 K, which suggests a reduced crystal structure symmetry. This neutron-scattering work provides a direct, well-refined experimental characterization of the magnetic and crystal structures that are crucial to the understanding of the unconventional magnetism exhibited in this unusual magnetic insulator.

the version appeared in PRB

References in corpus (8)

• Mott Insulators in the Strong Spin-Orbit Coupling Limit: From Heisenberg to a Quantum Compass and Kitaev Models
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Cited by in corpus (1)

• Microscopic and Spectroscopic Evidence for a Slater Metal-Insulator Transition in Sr2IrO4