Magnetic skyrmions with nontrivial topologies have great potential to serve as memory cells in novel spintronic devices. Small skyrmions were theoretically and experimentally confirmed to be generated under the influence of external fields in ferrimagnetic films via Dzyaloshinskii–Moriya interactions (DMIs). However, this topological state has yet to be verified in ferrimagnetic crystals, especially in the absence of external fields and DMIs. Here, spontaneous biskyrmions were directly observed in the Tb_0.2Gd_0.8Co₂ ferrimagnetic crystal with a Kagome lattice using Lorentz transmission electron microscopy. The high-density biskyrmions exhibited a small size (approximately 50 nm) over a wide temperature range, were closely related to subtle magnetic interaction competition, and coexisted with some broken stripes that could be easily converted into zero-field biskyrmions by utilizing proper field-cooling manipulation. These results can be used to establish a platform for investigating functional sub-50-nm skyrmions in ferrimagnetic crystals and to facilitate advanced applications in magnetic devices.

具有非平凡拓扑的磁性斯格明子具有作为新型自旋电子器件中的存储单元的巨大潜力。理论上和实验均证实，亚铁磁薄膜中的小斯格明子是在外部场的影响下通过 Dzyaloshinskii-Moriya 相互作用（DMIs）产生的。然而，这种拓扑状态尚未在亚铁磁晶体中得到验证，特别是在没有外部场和 DMI 的情况下。_{这里，使用洛伦兹透射电子显微镜在具有Kagome晶格的Tb 0.2} Gd _0.8 Co ₂亚铁磁晶体中直接观察到自发双斯格明子。高密度双斯格明子在较宽的温度范围内表现出较小的尺寸（约50 nm），与微妙的磁相互作用竞争密切相关，并与一些破碎的条纹共存，利用适当的场可以很容易地将其转化为零场双斯格明子。冷却操纵。这些结果可用于建立一个平台，用于研究亚铁磁晶体中的功能性亚 50 nm 斯格明子，并促进磁性器件中的高级应用。