Real-space observation of fluctuating antiferromagnetic domains

Min Gyu Kim; Andi Barbour; Wen Hu; Stuart B Wilkins; Ian K Robinson; Mark P M Dean; Junjie Yang; Choongjae Won; Sang-Wook Cheong; Claudio Mazzoli; Valery Kiryukhin

doi:10.1126/sciadv.abj9493

Real-space observation of fluctuating antiferromagnetic domains

Sci Adv. 2022 May 27;8(21):eabj9493. doi: 10.1126/sciadv.abj9493. Epub 2022 May 27.

Authors

Min Gyu Kim^{1

2}, Andi Barbour³, Wen Hu³, Stuart B Wilkins³, Ian K Robinson⁴, Mark P M Dean⁴, Junjie Yang⁵, Choongjae Won^{6

7}, Sang-Wook Cheong^{1

6

7

8}, Claudio Mazzoli³, Valery Kiryukhin¹

Affiliations

¹ Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA.
² Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.
³ National Synchrotron Light Source II, Brookhaven National Laboratory, Upton, NY 11973, USA.
⁴ Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratory, Upton, NY 11973, USA.
⁵ Department of Physics, New Jersey Institute of Technology, Newark, NJ 07102, USA.
⁶ Max Planck POSTECH/Korea Research Initiative, Pohang University of Science and Technology, Pohang 37673, Korea.
⁷ Laboratory of Pohang Emergent Materials, Department of Physics, Pohang University of Science and Technology, Pohang 37673, Korea.
⁸ Rutgers Center for Emergent Materials, Rutgers University, Piscataway, NJ 08854, USA.

Abstract

Magnetic domains play a fundamental role in physics of magnetism and its technological applications. Dynamics of antiferromagnetic domains is poorly understood, although antiferromagnets are expected to be extensively used in future electronic devices wherein it determines the stability and operational speed. Dynamics of antiferromagnets also features prominently in the studies of topological quantum matter. Real-space imaging of fluctuating antiferromagnetic domains is therefore highly desired but has never been demonstrated. We use coherent x-ray diffraction to obtain videos of fluctuating micrometer-scale antiferromagnetic domains in Ni₂MnTeO₆ on time scales from 10^-1 to 10³ s. In the collinear phase, thermally activated domain wall motion is observed in the vicinity of the Néel temperature. Unexpectedly, the fluctuations persist through the full range of the higher-temperature helical phase. These observations illustrate the high potential significance of the dynamic domain imaging in phase transition studies and in magnetic device research.