Above-Room-Temperature Strong Ferromagnetism in 2D MnB Nanosheet

Two-dimensional (2D) room-temperature (RT) ferromagnetic materials have amassed considerable interest in the field of fundamental physics for applications in next-generation spintronic devices owing to their physical properties. However, realizing strong RT ferromagnetism and a high Curie temperature (T-C) in these 2D magnetic materials remains challenging. Herein, we develop a 2D MnB nanosheet for known 2D ferromagnets that demonstrates strong RT ferromagnetism and a record-high above-RT T-C of similar to 585.9 K. Through magnetic force microscopy, clear evidence of ferromagnetic behavior is observed at room temperature. Structural characterization and density functional theory calculations further reveal that (i) after exfoliation of bulk, -OH functional groups were introduced in addition to Mn-B bonds being formed, which increases MnB nanosheet T-C to 585.9 K and (ii) the d(3)up arrow spin configuration of Mn mainly contributed to the magnetic moment of MnB, and the hybridization between the d(xz) (d(yz)) and d(z)(2) orbitals of the Mn atom provides a large contribution to magnetic anisotropy, which stabilizes the magnetic property of MnB. Our findings establish a strong experimental foundation for 2D MnB nanosheets as ideal materials for the construction of spintronic devices.