Investigations of Half-Metallicity Among Doped and Un-Doped Graphene Nanostructures in Different Conformations for Spintronics Applications
No Thumbnail Available
Date
2012-06
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa Universty
Abstract
We have investigated the phenomenal of half-metallicity among various novel
conformations of graphene nanoribbons (GNRs). The Density of States (DOS) and the
Transmission spectrum (TS) of zigzag GNRs doped with boron (B), Nitrogen (N) and
Oxygen (O) atoms and undoped but with vacancies are independently investigated by
first-principle calculations. A new scheme of spin diode architecture is identified to
achieve half-metallicity in ZGNRs by doping B atoms at one edge and N atoms at the
other as well as B atom at one edge and O atom at the other edge. We found that the
origin of the nearly half-metallic state is due to interactions between the edge states and
B-N or B-O atoms which provide direct control over the electron occupation of the edge
states by inducing large chemical potential difference between the edge states. We have
also found that the ZGNR spintronicity is vacancy concentration dependent. Particularly,
for single vacancy site the FM coupling among the zigzag edges are more favorable,
while double vacancy sites are found to promote the AFM edge coupling. The as
mentioned results of the nearly half-metallicity are presented in the thesis by
corroborating them with the results of spin polarization. The prospects of nearly half
metallic results are also discussed in context to mangetoresistive device performance.
Description
Keywords
Half-Metallicity Among