发表机构
Dalian University of Technology; South China Normal University; Tsinghua University（大连理工大学; 华南师范大学; 清华大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本研究通过分子束外延生长CrSb薄膜，发现维度降低导致交替磁性消失并涌现铁磁性，为自旋电子器件提供超薄磁态工程平台。
AI 中文摘要
交替磁体通过将自旋分裂电子态与零净磁化相结合，为自旋电子器件提供了一条有前景的途径，但维度降低如何重塑其磁序仍知之甚少。在此，我们通过分子束外延直接在SrTiO3(001)衬底上生长双层厚度的CrSb(0001)薄膜，并发现了一种意外的厚度依赖磁性转变。单双层薄膜表现出具有强垂直磁各向异性的室温铁磁性，而双层薄膜中的铁磁性消失，与块体CrSb的交替磁基态形成鲜明对比。密度泛函理论计算揭示，暴露的Cr表面引起轨道重排，增强了层内铁磁交换，同时抑制了竞争的层间反铁磁耦合，从而驱动了从交替磁性到铁磁性的维度交叉。这些发现确立了维度和表面终止作为磁序的强大控制手段，并为工程化用于自旋电子应用的超薄磁态提供了平台。
英文摘要
Altermagnets offer a promising route to spintronic devices by combining spin-split electronic states with zero net magnetization, but how reduced dimensionality reshapes their magnetic order remains poorly understood. Here, we grow bilayer-thickness CrSb (0001) films directly on SrTiO3(001) substrates by molecular beam epitaxy and uncover an unexpected thickness-dependent magnetic transition. The one-bilayer films exhibit room-temperature ferromagnetism with strong perpendicular magnetic anisotropy, whereas ferromagnetism vanishes in two-bilayer films, contrasting sharply with the altermagnetic ground state of bulk CrSb. Density functional theory calculations reveal that the exposed Cr surface induces orbital rearrangement that strengthens intralayer ferromagnetic exchange while suppressing competing interlayer antiferromagnetic coupling, driving the dimensional crossover from altermagnetism to ferromagnetism. These findings establish dimensionality and surface termination as powerful controls of magnetic order and provide a platform for engineering ultrathin magnetic states for spintronic applications.
DOI：10.1016/j.newton.2026.100700
