Electronic and magnetic properties of multishell Co nanowires coated with Cu

TL;DR

This study investigates how coating ultrathin Co nanowires with Cu affects their electronic and magnetic properties, revealing structural preferences and magnetic variations due to Cu layers using computational models.

Contribution

It provides new insights into the structural and magnetic behavior of Cu-coated Co nanowires, highlighting the effects of Cu layers on magnetic moments and atomic arrangements.

Findings

Cu atoms prefer surface occupation at specific compositions

Cu coating reduces magnetic moments of interior Co atoms

A nonmagnetic Co atom row appears with two Cu layers

Abstract

The structural, electronic, and magnetic properties of ultrathin Cu-coated Co nanowires have been studied by using empirical genetic algorithm simulations and a tight-binding $spd$ model Hamiltonian in the unrestricted Hartree-Hock approximation. For some specific stoichiometric compositions, Cu atoms occupy the surface, while Co atoms prefer to stay in the interior, forming the perfect coated multishell structures. The outer Cu layers lead to substantial variations of the magnetic moment of interior Co atoms, depending on the structure and thickness of Cu layers. In particular, single Co atom row in the center of nanowire is found to be nonmagnetic when coated with two Cu layers. All the other Co nanowires in the coated Cu shell are still magnetic but the magnetic moments are reduced as compared with Co nanowires without Cu coating. The interaction between Cu and Co atoms induces nonzero magnetic moment for Cu atoms.