Thermal fluctuations in magnetic domain in the van der Waals antiferromagnet NiPS₃

NiPS3 is an XXZ-type van der Waals material with an antiferromagnetic transition at 150 K. It is easily exfoliated in monolayer due to relatively weak van der Waals interlayer bonding, which realizes the two-dimensional magnet in real space. To probe the magnetic order and local electronic state in NiPS3, we investigate the exfoliated NiPS3 with a photoemission microscope with linearly polarized x-rays. In this work, we observe the magnetic domain in the van der Waal antiferromagnet NiPS3. We confirm the domains originate from the magnetic order by temperature dependency. The domain contrasts decrease as the temperature increases. Above Neel temperature, the domain contrasts get very weak or vanish. In addition, the thermal fluctuation of magnetic domain is captured. When cooled down, multi-domains merge into one domain.