Low-amplitude, force gradient imaging of Cu(100) surface using tunnel current feedback

Oral, Ahmet
The large corrugation amplitudes in scanning tunnelling microscope (STM) images of metal surfaces have been commonly attributed to the action of forces between the tip and the sample. We have investigated the Cu(100) surface using a high-resolution non-contact atomic force microscope/scanning tunnelling microscope (nc-AFM/STM) in UHV. Force gradient and STM topography images were acquired simultaneously using constant tunnelling current feedback. Force gradient images showed atomic resolution whereas STM scans exhibited almost no contrast, corresponding to a flat tip trajectory during scans. The corrugation height in force gradient images was found to increase as the set tunnelling current was increased. Force gradient and tunnel current were directly measured as a function of separation, to determine the operating conditions during imaging. The STM operation regime is found to lie between the minimum of the stiffness curve and the start of repulsive force.


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Structural and optoelectronic properties of silicon (Si) nanowire-silver indium selenide (AgInSe2) thin film heterojunctions were investigated. The metal-assisted etching method was employed to fabricate vertically aligned Si nanowire arrays. Stoichiometric AgInSe2 films were then deposited onto the nanowires using co-sputtering and sequential selenization techniques. It was demonstrated that the three-dimensional interface between the Si nanowire arrays and the AgInSe2 thin film significantly improved the ...
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Anomalous superlattice dark-field images of composite precipitates consisting of a dark core surrounded by a bright shell in Al-2.52Li-0.15Zr alloys, has been investigated by many beam dynamical image simulations employing a scattering matrix approach. The coherency strain field in the shell of the precipitate, as well as in the matrix, has been calculated by use of relations derived, and these are incorporated into the image calculations to determine whether the unexpected images can be elucidated by the c...
Prevention of sidewall redeposition of etched byproducts in the dry Au etch process
Aydemir, A.; Akın, Tayfun (IOP Publishing, 2012-07-01)
In this paper we present a new technique of etching thin Au film in a dual frequency inductively coupled plasma (ICP) system on Si substrate to prevent the redeposition of etched Au particles over the sidewall of the masking material known as veils. First, the effect of the lithography step was investigated. Then the effects of etch chemistry and the process parameters on the redeposition of etched Au particles on the sidewall of the masking material were investigated. The redeposition effect was examined b...
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High-performance InSb micro-HaIl sensors were fabricated by optical lithography and incorporated in a room-temperature scanning Hall probe microscope for imaging of localized magnetic fluctuations in close proximity to the surfaces of crystalline uniaxial garnet films. The room-temperature noise figure of the InSb sensors was 6-10 mG/v/Hz, which is an order of magnitude better than GaAs-AlGaAs two-dimensional electron gas sensors used to date.
Direct measurement of charge transport through helical poly(ethyl propiolate) nanorods wired into gaps in single walled carbon nanotubes
Wang, Nan; Yano, Koji; Durkan, Colm; Plank, Natalie; Welland, Mark E.; Zhang, Yan; Ünalan, Hüsnü Emrah; Mann, Mark; Amaratunga, G. A. J.; Milne, William I. (IOP Publishing, 2009-03-11)
We report the direct measurement of electrical transport through rod-like polymer molecules, of poly(ethyl propiolate) (PEP), utilizing single walled carbon nanotubes (SWNTs) as electrodes. The electrical properties of the devices were measured (i) before cutting a SWNT, (ii) when a SWNT was cut and (iii) after PEP deposition into the nanoscale gap in a cut SWNT. The gate-dependent electrical properties showed a reduction in current from I-on = 2.4 x 10(-7) A for SWNT devices to I-on = 3.6 x 10(-9) A for PE...
Citation Formats
H. Ö. ÖZER, A. NORRİS, A. Oral, P. M. HOFFMANN, and J. B. PETHİCA, “Low-amplitude, force gradient imaging of Cu(100) surface using tunnel current feedback,” NANOTECHNOLOGY, pp. 0–0, 2004, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/48033.