Abstract
Two-dimensional (2D) magnetic materials are essential to developing high-performance spintronic devices. Recent experimental discoveries of several atomic thin 2D ferromagnetic materials have stimulated great interest in further exploring this fascinating class of materials. Here, combining an advanced crystal structure search method and extensive first-principles energetic and dynamic calculations, we have identified a planar ${\mathrm{CoB}}_{6}$ monolayer as a stable 2D ferromagnet. We show that the ferromagnetic ground state of the ${\mathrm{CoB}}_{6}$ monolayer remains robust in the ambient environment, and the magnetic stability and moment can be remarkably enhanced and tuned by external strain. Moreover, we propose feasible synthesis routes for the the newly predicted ${\mathrm{CoB}}_{6}$ monolayer, either by Co atom adsorption on the recently proposed ${\ensuremath{\delta}}_{4}$ boron sheet or by direct chemical growth. The present results establish a fundamental material and physics basis for synthesis and characterization of the ${\mathrm{CoB}}_{6}$ monolayer among the emerging 2D ferromagnetic materials.
Highlights
Spintronics utilizes electron spin instead of charge for information storage, transport, and processing, and it holds great promise for next-generation high-performance devices with superior characteristics such as high processing speed and low power consumption
We examined over 1000 CoxBy (x, y = 1–6) structures based on the particle-swarm optimization (PSO) structure search; all these structures were fully relaxed using the VASP code [42], and their dynamical stabilities were checked by phonon calculations
The corresponding density of states (DOS) from the adsorbed molecules stay far away from the Fermi level [Figs. 4(e) and 4(f)], and the magnetic moment remains nearly the same as in the pristine CoB6 monolayer (Fig. S11 [56]). These results show that the ferromagnetic ground state of the CoB6 monolayer can survive, and even thrive, in the ambient environment
Summary
Spintronics utilizes electron spin instead of charge for information storage, transport, and processing, and it holds great promise for next-generation high-performance devices with superior characteristics such as high processing speed and low power consumption. Research and development in the materials physics fields related to spintronics have attracted intensive interest from both fundamental and practical sides in recent decades [1]. Practical materials for spintronic applications should possess strong structural and magnetic stability, high Curie temperature, high spin polarization ratio, and feasibility for experimental fabrication. Recent studies have predicted a number of nanoscale ferromagnetic materials, such as the Fe2Si sheet [2], MXene [3], strained NbS2 and NbSe2 [4], and defective or partially hydrogenated graphene [5,6,7]; ferromagnetic materials that meet the criteria for practical device implementation have been difficult to obtain due to challenges in material synthesis and stability. The magnetism of a 2D CrI3 layer has been shown to be controllable by electrostatic
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
