Kim Min Gyu, Barbour Andi, Hu Wen, Wilkins Stuart B, Robinson Ian K, Dean Mark P M, Yang Junjie, Won Choongjae, Cheong Sang-Wook, Mazzoli Claudio, Kiryukhin Valery
Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, USA.
Department of Physics, University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USA.
Sci Adv. 2022 May 27;8(21):eabj9493. doi: 10.1126/sciadv.abj9493.
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 NiMnTeO on time scales from 10 to 10 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.
磁畴在磁学物理及其技术应用中起着基础性作用。尽管反铁磁体有望在未来电子设备中得到广泛应用，且其动力学特性决定了设备的稳定性和运行速度，但目前人们对反铁磁畴的动力学了解甚少。反铁磁体的动力学在拓扑量子物质研究中也具有重要意义。因此，人们非常希望能够对波动的反铁磁畴进行实空间成像，但这一点从未得到证实。我们利用相干X射线衍射技术，在10到10秒的时间尺度上获取了NiMnTeO中波动的微米级反铁磁畴的视频。在共线相中，在奈尔温度附近观察到热激活畴壁运动。出乎意料的是，这些涨落在高温螺旋相的整个范围内持续存在。这些观察结果说明了动态畴成像在相变研究和磁器件研究中的潜在重要意义。
