Intrinsic multiferroicity in molybdenum oxytrihalides nanowires

Low-dimensional multiferroics, which simultaneously possess at least two primary ferroic order parameters, hold great promise for post-Moore electronic devices. However, intrinsic one-dimensional (1D) multiferroics with the coexistence of ferroelectricity and ferromagnetism are still yet to be realized, which will be not only crucial for exploring the interplay between low-dimensionality and ferroelectric/ferromagnetic ordering but also significant in rendering application approaches for high density information technologies. Here, we present a theoretical prediction of intrinsic multiferroicity in 1D molybdenum oxytrihalides nanowires, especially focusing on MoOBr3 nanowires which could be readily extracted from experimentally synthesized van der Waals MoOBr3 bulk materials. Due to the spatial inversion symmetry spontaneously broken by Mo atoms’ displacements, MoOBr3 nanowires exhibit 1D ferroelectricity with small coercive electric field and exceptional Curie temperature (~570 K). Additionally, MoOBr3 nanowires also possess 1D antiferroelectric metastable states. On the other hand, both ferroelectric and antiferroelectric MoOBr3 nanowires exhibit ferromagnetic ordering on account of the half-filled Mo-dyz orbitals, a moderate tensile strain (~5%) can greatly boost the spontaneous polarization (~40%) and a mild compress strain (~−2%) may readily switch the magnetic easy axis of ferroelectric MoOBr3 nanowires. Our work holds potential candidates for developing innovative devices that exploit intrinsic multiferroic properties, enabling advancements in novel electronic and spintronic applications.