Interstitial Transition Metal Doping in Hydrogen Saturated Silicon Nanowires

TL;DR

This study uses first principles calculations to explore how transition metal doping affects the electronic and magnetic properties of hydrogen-saturated silicon nanowires, revealing potential for spintronic applications.

Contribution

It provides a systematic analysis of transition metal doping effects on hydrogenated silicon nanowires, including magnetic and electronic property changes, confirmed by multiple computational methods.

Findings

Most TM-doped H-SiNWs become ferromagnetic metals.

Certain dopings exhibit half-metallic behavior.

Ti doping results in a non-magnetic system.

Abstract

We report a first principles systematic study of atomic, electronic, and magnetic properties of hydrogen saturated silicon nanowires (H-SiNW) which are doped by transition metal (TM) atoms placed at various interstitial sites. Our results obtained within the conventional GGA+U approach have been confirmed using an hybrid functional. In order to reveal the surface effects we examined three different possible facets of H-SiNW along [001] direction with a diameter of ~2nm. The energetics of doping and resulting electronic and magnetic properties are examined for all alternative configurations. We found that except Ti, the resulting systems have magnetic ground state with a varying magnetic moment. While H-SiNWs are initially non-magnetic semiconductor, they generally become ferromagnetic metal upon TM doping. Even they posses half-metallic behavior for specific cases. Our results suggest that H-SiNWs can be functionalized by TM impurities which would lead to new electronic and spintronic devices at nanoscale.