Anisotropy of Antiferromagnetic Domains in a Spin-orbit Mott Insulator

TL;DR

This study uses advanced x-ray imaging to reveal how antiferromagnetic domains in a spin-orbit Mott insulator change with temperature, highlighting anisotropic behaviors crucial for understanding magnetic properties.

Contribution

It introduces a novel 3D imaging technique to observe temperature-dependent antiferromagnetic domain evolution in $Sr_2IrO_4$, revealing anisotropic domain shape changes.

Findings

Antiferromagnetic domains exhibit anisotropic shape changes with temperature.

The anisotropy reflects the underlying magnetic coupling strength.

3D domain imaging offers new insights into magnetic behavior in complex materials.

Abstract

The temperature-dependent behavior of magnetic domains plays an essential role in the magnetic properties of materials, leading to widespread applications. However, experimental methods to access the three-dimensional (3D) magnetic domain structures are very limited, especially for antiferromagnets. Over the past decades, the spin-orbit Mott insulator iridate $Sr_2IrO_4$ has attracted particular attention because of its interesting magnetic structure and analogy to superconducting cuprates. Here, we apply resonant x-ray magnetic Bragg coherent diffraction imaging to track the real-space 3D evolution of antiferromagnetic ordering inside a $Sr_2IrO_4$ single crystal as a function of temperature, finding that the antiferromagnetic domain shows anisotropic changes. The anisotropy of the domain shape reveals the underlying anisotropy of the antiferromagnetic coupling strength within $Sr_2IrO_4$. These results demonstrate the high potential significance of 3D domain imaging in magnetism research.