Title
Fabrication of ultra-sharp tips from carbon fiber for scanning tunneling microscopy investigations of epitaxial graphene on 6H-SiC(0 0 0 1) surface
Date Issued
2015
Access level
restricted access
Resource Type
journal article
Author(s)
Morán Meza J.A.
Lubin C.
Thoyer F.
Martin F.
Cousty J.
Publisher(s)
Elsevier Ltd
Abstract
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. © 2015 Elsevier Ltd. All rights reserved.
Start page
363
End page
370
Volume
86
Number
9
Language
English
Subjects
Scopus EID
2-s2.0-84924565690
Source
Carbon
ISSN of the container
0008-6223
Sponsor(s)
José Antonio Morán Meza would also like to acknowledge financial support from the Peru’s National Council of Science and Technology (Concytec), the Réseau Thématique de Recherche Avancée (RTRA-Triangle de la Physique), and the CEA/Direction des Relations Internationales (DRI).
Sources of information:
Directorio de Producción Científica