Fabrication of ultra-sharp tips from carbon fiber for scanning tunneling microscopy investigations of epitaxial graphene on 6H-SiC(0 0 0 1) surface

J. A. Morán Meza, C. Lubin, F. Thoyer, K. A. Villegas Rosales, A. A. Gutarra Espinoza, F. Martin, J. Cousty

Resultado de la investigación: Contribución a una revistaArtículo (Contribución a Revista)revisión exhaustiva

6 Citas (Scopus)

Resumen

Abstract The fabrication of ultra-sharp tips from carbon fiber (CF), which are mounted on a qPlus probe for combined dynamic scanning tunneling microscopy (STM) and frequency modulation atomic force microscopy (FM-AFM) experiments, is reported. The carbon fiber tips were electrochemically etched in a KOH or NaOH solution, using different electronic devices. CF tips with an apex radius ∼10 nm, as deduced from the measured slopes of the Fowler-Nordheim plots (kR < 70 nm for k ∼ 6), were routinely obtained with a homemade electronic device that controls the intensity of the etching current. Then, these conductive CF tips were also characterized by imaging the 6H-SiC(0 0 0 1) surface covered by an epitaxial graphene layer in ultra-high vacuum (UHV). The lattice of the (63×63) R30 reconstruction was regularly imaged by STM working either in non-oscillating mode or in dynamic mode, which also maps the variations of the force gradient. From these measurements with a constant mean-tunneling-current of 20 pA, it was found that the STM tip suffered variations of the tip/surface force gradient in between 8.25 and 16.50 N/m when it scanned the epitaxial graphene layer on the reconstructed 6H-SiC(0 0 0 1) surface.

Idioma originalInglés
Número de artículo9674
Páginas (desde-hasta)363-370
Número de páginas8
PublicaciónCarbon
Volumen86
DOI
EstadoPublicada - 1 may 2015
Publicado de forma externa

Huella Profundice en los temas de investigación de 'Fabrication of ultra-sharp tips from carbon fiber for scanning tunneling microscopy investigations of epitaxial graphene on 6H-SiC(0 0 0 1) surface'. En conjunto forman una huella única.

Citar esto