Robust room-temperature ferromagnetism in two-dimensional ZrCl nanoplates

Two-dimensional (2D) magnetic materials provide a versatile platform for spintronic and quantum applications, but achieving stable ferromagnetism over a broad temperature range remains a major challenge. Here, we report the discovery of 2D ZrCl nanoplates with robust ferromagnetism persisting up to 400 K, demonstrating intrinsic magnetism in zirconium-based 2D compounds for the first time. A solvation-based method was developed to crystallize 2D ZrCl nanoplates within confined reduced graphene oxide membranes under ambient conditions, where cation–π interactions facilitate both cation accumulation and structural stabilization. Both first-principles calculations and transmission electron microscopy confirm that 2D ZrCl crystallizes in the tetragonal space group P4 mm, and electronic structure calculations indicate a ferromagnetic state. Room-temperature ferromagnetism is confirmed by magnetic hysteresis loops up to 400 K, with support from the theoretically predicted van Hove singularity near the Fermi level. These results broaden the material landscape of 2D magnetism and establish an effective strategy for discovering new 2D magnetic materials.