Spin and surface orientation effects of work function for Cr/Ni(111), Cr/Ni(100) and Cr/Ni(110) metal gates

Abstract

Work functions of Cr/Ni (111), Cr/Ni (100) and Cr/Ni (110) surfaces with different magnetic configurations for Cr atoms in the topmost Cr monolayer are investigated using first-principles methods based on density functional theory. The calculated results reveal that work functions vary with crystal orientations and magnetic configurations. The magnitude of the Cr magnetic moments for the three (111), (100) and (110) surfaces follows a change trend with M Cr, Cr/Ni(111) < M Cr, Cr/Ni(100) < M Cr, Cr/Ni(110) . Altering the magnetic configurations of the systems from an original ground state to an excited one will have the total energy and the Fermi level increase. Consequently, it will give rise to the reduction of the work function for the system. Moreover, the quite favorable variation range (4.92–4.41 eV) of the calculated work functions for Cr/Ni (100) system modulated by spin effect implies that the Cr/Ni (100) system may be a more promising candidate. Our work suggests that changing magnetic configurations can modulate the work functions of magnetic metal gates well.