Emergence of strong ferromagnetism in silicene nanoflakes via patterned hydrogenation and its potential application in spintronics

Considerably different properties emerge in nanomaterials as a result of quantum confinement and edge effects. In this study, the electronic and magnetic properties of quasi zero-dimensional silicene nano-flakes (SiNFs) are investigated using density functional theory (DFT) calculations. While the zigzag-edged hexagonal SiNFs exhibit non-magnetic semiconducting character, the zigzag-edged triangular SiNFs are magnetic semiconductors. One effective method of harnessing the properties of silicene is hydrogenation owing to its reversibility and controllability. From bare SiNFs to half-hydrogenated and then to fully hydrogenated, a triangular SiNF experiences a change from ferrimagnetic to very strong ferromagnetic, and then to non-magnetic. Nonetheless, a hexagonal SiNF undergoes a transfer from nonmagnetic to very strong ferromagnetic, then to non-magnetic. The half-hydrogenated SiNFs produce a large spin moment that is directly proportional to the square of the flake's size. It has been revealed that the strongly induced spin magnetizations align parallel and demonstrates a collective character by large range ferromagnetic exchange coupling, giving rise to its potential use in spintronic circuit devices. Spin switch models are offered as an example of one of the potential applications of SiNFs in tuning the transport properties by controlling the hydrogen coverage. (C) 2017 Elsevier B.V. All rights reserved.