Abstract:

Layered transition-metal compounds (LTMCs) feature stacked architectures, strong magnetic anisotropy, and tunable magnetic order, making them promising material platforms for low-power spintronic technologies and for enabling topological functionalities in the post-Moore era. Here we review recent progress on two-dimensional (2D) magnetism in LTMCs, emphasizing material taxonomy, intrinsic magnetic properties, and external-field controls. This review first presents a classification of LTMCs by crystal structure and chemistry —binary halides, chalcogenides, and ternary families (e.g., MPX₃, MmXnTek, MnBi₂Te₄) —followed by a summary of their coupling mechanisms, ordering temperatures, and dimensional effects. It then analyzes the modulation of exchange interactions, magnetic anisotropy, and topological states by electric-field gating, strain engineering, and ion intercalation, with representative experimental demonstrations. Notable advances include room-temperature ferromagnetic metals and semiconductors, observation of the quantum anomalous Hall effect (QAHE) in MnBi₂Te₄, and synergistic control of magnetic-topological states under multiple external stimuli. Persistent challenges involve the limited availability of intrinsic 2D magnetic semiconductors with high Curie temperatures (TC), incomplete understanding of the microscopic couplings at interfaces and under quantum confinement, and device-level stability. We conclude by outlining opportunities that lie in the integration of multiscale characterization, first-principles theory, and cross-scale fabrication to precisely co-engineer magnetism, topology, and electronic structure, thereby advancing LTMCs toward spintronic and topological-quantum applications

Key words:  , layered transition-metal compounds, two-dimensional magnetism, electric-field control, strain engineering, ion intercalation, topological magnetism, quantum anomalous Hall effec