Title: The tight-binding model study of the role of electron occupancy on the ferromagnetic gap in graphene-on-substrate

Authors: Rashmirekha Swain; Sivabrata Sahu; G.C. Rout

Addresses: Department of Physics, School of Applied Sciences, KIIT University, Campus-3, 751024, Odisha, India ' Center of Excellence for Novel Energy Materials, School of Basic Sciences, Indian Institute of Technology Bhubaneswar, Odisha, India ' P.G. Department of Applied Physics and Ballistics, Fakir Mohan University, Vyasa Vihar, Balasore, India

Abstract: We propose here a theoretical model for graphene in its ferromagnetic phase. The Hamiltonian describes electron hoppings up-to-third-nearest neighbours for graphene-on-substrate. The sub-lattice coulomb interactions within mean-field approach involve the total electron occupancy and ferromagnetic magnetisations (FMs). The temperature dependent ferromagnetic magnetisation and hence, the ferromagnetic gap are derived from the electron Green's functions and are solved self-consistently. The result shows that the magnitude of the ferromagnetic gap and the critical coulomb interaction strongly depend on total electron occupancy. The critical coulomb interaction decreases with increase of electron occupancy and the vice-versa.

Keywords: graphene; ferromagnetic gap; coulomb potential.

DOI: 10.1504/IJNBM.2019.097592

International Journal of Nano and Biomaterials, 2019 Vol.8 No.1, pp.44 - 53

Available online: 22 Jan 2019 *

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