Surface-induced magnetism in C-doped SnO$_{2}$

TL;DR

This study uses first-principles calculations to show that carbon doping induces surface magnetism in SnO$_{2}$, with magnetic moments localized at the surface and subsurface atoms, but not in the bulk.

Contribution

It reveals that C-doping induces magnetism specifically at the SnO$_{2}$ (001) surface, highlighting the surface-specific magnetic behavior.

Findings

Magnetism appears only at the surface and subsurface when C is doped at surface oxygen sites.

Bulk C-doped SnO$_{2}$ does not exhibit magnetism.

Magnetic moments originate mainly from carbon atoms' $p$ orbitals.

Abstract

The magnetism of C-doped SnO$_{2}$ (001) surfaces is studied using first-principles calculations. It is found that carbon does not induce magnetism in bulk SnO$_{2}$ when located at the oxygen site, but shows a large magnetic moment at the SnO$_{2}$ (001) surface. The magnetic moment is mainly contributed by the carbon atoms due to empty minority spins of $p$ orbitals and is localized at the surface and subsurface atoms. No magnetism is observed when the carbon atom is located at the subsurface oxygen sites. The origin of magnetism is discussed in the context of surface bonding.