Graphite, graphene on SiC, and graphene nanoribbons: Calculated images with a numerical FM-AFM

• Fabien Castanié,
• Laurent Nony,
• Sébastien Gauthier and
• Xavier Bouju

Beilstein J. Nanotechnol. 2012, 3, 301–311, doi:10.3762/bjnano.3.34

• implemented with the n-AFM, advanced first-principles methods [92] are well adapted to deal with local changes of electronic structure when the tip interacts with the sample surface, especially for KPFM [93][94]. For weak chemical interactions and van der Waals forces, theoretical studies have demonstrated

Modeling noncontact atomic force microscopy resolution on corrugated surfaces

• Kristen M. Burson,
• Mahito Yamamoto and
• William G. Cullen

Beilstein J. Nanotechnol. 2012, 3, 230–237, doi:10.3762/bjnano.3.26

• quasi-1-D substrate corrugation (modeled as a sinusoid) and obtain the response of a spherical tip to van der Waals (vdW) interactions. To our knowledge, it is the first model to directly incorporate the lateral variation of van der Waals forces due to surface corrugation and to attempt to quantify this

• , using an approach that incorporates the IDL routines INTERPOLATE and INT_3D. As a check on this numerical integration, we compare against the exact analytical result for a sphere attracted to a flat surface by van der Waals forces. It is well-known that the sphere–plane Hamaker integration has the

• , we discussed the Hamaker integration for a sphere interacting with a flat surface through van der Waals forces. The integration can be carried out without approximation to yield the exact formula; this exact formula is cumbersome and given by Equation 10. In the limit z << R, this formula simplifies

An NC-AFM and KPFM study of the adsorption of a triphenylene derivative on KBr(001)

• Antoine Hinaut,
• Adeline Pujol,
• Florian Chaumeton,
• David Martrou,
• André Gourdon and
• Sébastien Gauthier

Beilstein J. Nanotechnol. 2012, 3, 221–229, doi:10.3762/bjnano.3.25

• voltage of the surrounding MLh domain. As expected the spatial resolution in the Kelvin map is lower than in the topography map due to the longer range of electrical forces relative to van der Waals forces. The different domains that appear in Figure 6 have been labeled and the monoatomic KBr steps

Theoretical study of the frequency shift in bimodal FM-AFM by fractional calculus

• Elena T. Herruzo and
• Ricardo Garcia

Beilstein J. Nanotechnol. 2012, 3, 198–206, doi:10.3762/bjnano.3.22

• length scale of the interaction force. For the force which appears in the DMT model [51] where H is the Hamaker constant of the long-range van der Waals forces, d0 is the equilibrium distance, R is the tip radius and Eeff is the effective Young’s modulus, which is related to the Young’s moduli Et and Es

STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• weak intermolecular van der Waals forces and molecule–substrate interactions, as well as intermolecular hydrogen bonding in the case of functionalized oligothiophenes [15][16][17]. The typical flat metallic substrates (HOPG, Au(111), Ag(111), etc.) employed in STM differ from the ITO electrodes used in

Distinguishing magnetic and electrostatic interactions by a Kelvin probe force microscopy–magnetic force microscopy combination

• Miriam Jaafar,
• Oscar Iglesias-Freire,
• Luis Serrano-Ramón,
• Manuel Ricardo Ibarra,
• Jose Maria de Teresa and
• Agustina Asenjo

Beilstein J. Nanotechnol. 2011, 2, 552–560, doi:10.3762/bjnano.2.59

• Table 1. The values have been calculated using Equation 2 and Equation 3 and the equation in [30]. For the van der Waals forces we assume a tip radius of 30 nm and AH of about 10−19 J. The electrostatic interaction is calculated for a tip with an electrical radius slightly smaller due to the existence

Switching adhesion forces by crossing the metal–insulator transition in Magnéli-type vanadium oxide crystals

• Bert Stegemann,
• Matthias Klemm,
• Siegfried Horn and
• Mathias Woydt

Beilstein J. Nanotechnol. 2011, 2, 59–65, doi:10.3762/bjnano.2.8

• ) has become a powerful tool for measuring the forces interacting between a sharp tip and a solid sample surface, such as van der Waals forces and short-range chemical forces [14][15][16][17]. Typically, the AFM is used for a spatially resolved imaging of forces, which requires a tip with a sharp apex

Defects in oxide surfaces studied by atomic force and scanning tunneling microscopy

• Thomas König,
• Georg H. Simon,
• Lars Heinke,
• Leonid Lichtenstein and
• Markus Heyde

Beilstein J. Nanotechnol. 2011, 2, 1–14, doi:10.3762/bjnano.2.1

• and van der Waals forces. The averaged frequency shift at the largest separation is about Δf = −0.52 Hz. By decreasing the tip-sample distance by 0.5 Å, the absolute value of the tunneling current and the frequency shift increase at the position of the defect. The tunneling current increases to It