Discovering more and new geometrically frustrated systems remains an active point of inquiry in fundamental physics for the existence of unusual states of matter. Here, we report spin-liquid-like behavior in a two-dimensional (2D) rhombic lattice Fe-metal-organic framework (Fe-MOF) with frustrated antiferromagnetism. This Fe-MOF exhibits a high frustration factor f = |θ_CW|/T_N ≥ 315, and its long-range magnetic order is suppressed down to 180 mK. Detailed theoretical calculations demonstrate strong antiferromagnetic coupling between adjacent Fe³⁺ ions, indicating the potential of a classical spin-liquid-like behavior. Notably, a T-linear heat capacity parameter, γ, originating from electronic contributions and with magnetic field independence up to 8 T, can be observed in the specific heat capacity measurements at low-temperature, providing further proof for the spin-liquid-like behavior. This work highlights the potential of MOF materials in geometrically frustrated systems, and will promote the research of exotic quantum physics phenomena.

Endowing bilayer transition-metal dichalcogenides (TMDs) with tunable magnetism is significant to investigate the coupling of multiple electron degrees of freedom (DOFs). However, effectively inducing and tuning the magnetic interaction of bilayer TMDs are still challenges. Herein, we report a strategy to tune the interlayer exchange interaction of centimeter-scale MoS₂ bilayer with substitutional doping of Co ion, by introducing sulfur vacancy (V_S) to modulate the interlayer electronic coupling. This strategy could transform the interlayer exchange interaction from antiferromagnetism (AFM) to ferromagnetism (FM), as revealed by the magnetic measurements. Experimental characterizations and theoretical calculations indicate that the enhanced magnetization is mainly because the hybridization of Co 3d band and V_S-induced impurity band alters the forms of interlayer orbital hybridizations between the partial Co atoms in upper and lower layers, and also enhances the intralayer FM. Our work paves the way for tuning the interlayer exchange interaction with defects and could be extended to other two-dimensional (2D) magnetic materials.