CPL - Chalmers Publication Library
| Utbildning | Forskning | Styrkeområden | Om Chalmers | In English In English Ej inloggad.

Scattering of flexural acoustic phonons at grain boundaries in graphene

Edit E. Helgee (Institutionen för teknisk fysik, Material- och ytteori) ; Andreas Isacsson (Institutionen för teknisk fysik, Kondenserade materiens teori)
Physical Review B (1098-0121). Vol. 90 (2014), 4,
[Artikel, refereegranskad vetenskaplig]

We investigate the scattering of long-wavelength flexural phonons against grain boundaries in graphene using molecular dynamics simulations. Three symmetric tilt grain boundaries are considered: one with a misorientation angle of 17.9 degrees displaying an out-of-plane buckling 1.5 nm high and 5 nm wide, one with a misorientation angle of 9.4 degrees and an out-of-plane buckling 0.6 nm high and 1.7 nm wide, and one with a misorientation angle of 32.2 degrees and no out-of-plane buckling. At the flat grain boundary, the phonon transmission exceeds 95% for wavelengths above 1 nm. The buckled boundaries have a substantially lower transmission in this wavelength range, with a minimum transmission of 20% for the 17.9 degrees boundary and 40% for the 9.4 degrees boundary. At the buckled boundaries, coupling between flexural and longitudinal phonon modes is also observed. The results indicate that scattering of long-wavelength flexural phonons at grain boundaries in graphene is mainly due to out-of-plane buckling. A continuum mechanical model of the scattering process has been developed, providing a deeper understanding of the scattering process as well as a way to calculate the effect of a grain boundary on long-wavelength flexural phonons based on the buckling size.



Denna post skapades 2014-08-19. Senast ändrad 2015-02-11.
CPL Pubid: 201621

 

Läs direkt!

Lokal fulltext (fritt tillgänglig)

Länk till annan sajt (kan kräva inloggning)


Institutioner (Chalmers)

Institutionen för teknisk fysik, Material- och ytteori (1900-2015)
Institutionen för teknisk fysik, Kondenserade materiens teori (1900-2015)

Ämnesområden

Fysik

Chalmers infrastruktur

Relaterade publikationer

Denna publikation ingår i:


Significance of grain boundaries for transport phenomena in graphene and proton-conducting barium zirconate


 


Projekt

Denna publikation är ett resultat av följande projekt:


Graphene-Based Revolutions in ICT And Beyond (GRAPHENE) (EC/FP7/604391)