Spontaneous Topological (Anti)meron Chains in the Domain Walls of Centrosymmetric Rare-Earth Magnet

Exploration and manipulation of topological protected magnetic swirls, such as skyrmion, antiskyrmion, meron, and vortex, holds significance for fundamental research and practical applications in high-density magnetic information storage and spintronics because of their high storage density and low driven current. This study unveils the existence of field-free spontaneous (anti)meron chains with a topological charge of +/- 1/2 in the centrosymmetric rare-earth magnet Tb6Co2.17Si2.5 via in situ real-space observation. The spin reorientation transition from in-plane to uniaxial anisotropy contributes to the spontaneous transformation from straight domain walls to topological (anti)meron chains and to stripe domains along the [110] zone axis during in situ cooling. The study further confirms the critical role of the noncollinear magnetic structure of Tb atoms in the formation of topological (anti)meron chains via real-space observations, first-principles calculations, and micromagnetic simulations. The spontaneous topological magnetic texture is strongly correlated with the 4f electrons of rare-earth atoms, enriching and stimulating alternative generation mechanisms of topological spin textures from emerging rare-earth magnets, and further applications in spintronics. Field-free topological (anti)meron chains with a topological charge of +/- 1/2 due to the noncollinear magnetic structure of Tb atoms are observed in centrosymmetric rare-earth magnet Tb6Co2.17Si2.5. The topological magnetic texture is strongly correlated with the 4f electrons of rare-earth atoms, enriching and stimulating alternative generation mechanisms of topological spin textures from emerging rare-earth magnets, and further applications in spintronics. image