Non-contact atomic force microscope in ultra high vacuum using radiation pressure excitation of cantilever with Fabry-Perot interferometer

Karagöz, Ercan
In this study Non-Contact Atomic Force Microscope (NC-AFM) imaging was performed by excitation of the cantilever via radiation pressure in a custom Ultra-High Vacuum (UHV) system. Both the excitation of the cantilever and the measurement of the deflection of the cantilever were done by employing a fiber Fabry-Pérot interferometer obtained by a TiO2 coating of the fiber end. This coating allows for a several times higher interference slope. The second normal mode of the cantilever oscillation, along with the first mode was clearly observed by excitation via radiation pressure without spurious peaks with Fabry-Pérot interferometer for the first time. By comparing the results of the cantilever spring constant measurements obtained by thermal excitation and radiation pressure excitation amplitude modulation, the reliability of the method of excitation by radiation pressure was shown. In order to test the interferometer a highly ordered pyrolytic graphite (HOPG) sample was imaged by exciting the cantilever with piezo-acoustic excitation. Then imaging experiments were carried out for obtaining atomic resolution image of a clean Si(111) (7x7) surface by exciting the cantilever with radiation pressure. 


Non-contact atomic force microscope (ncafm) operation in uhv using radiation pressure excitation of cantilever
Uysallı, Yiğit; Turan, Raşit; Yerci, Selçuk; Department of Physics (2016)
In this work a new method for excitation of Non-Contact Atomic Force Microscope (NCAFM) cantilevers by means of radiation pressure was developed and applied for NCAFM imaging for the first time in the world. Piezo excitation is the most common method of cantilever excitation in AFM devices. However, it has few drawbacks, sometimes spurious resonance peaks and non-ideal Lorentzian curves can be observed. Radiation pressure has earlier been used for calibration of AFM cantilevers but has never been used for i...
Quantitative atom-resolved force gradient imaging using noncontact atomic force microscopy
Oral, Ahmet; ÖZER, HAKAN ÖZGÜR; HOFFMANN, PM; PETHICA, JB (2001-09-17)
Quantitative force gradient images are obtained using a sub-angstrom amplitude, off-resonance lever oscillation method during scanning tunneling microscopy imaging. We report the direct observation of short-range bonds, and the measured short-range force interaction agrees well in magnitude and length scale with theoretical predictions for single bonds. Atomic resolution is shown to be associated with the presence of a prominent short-range contribution to the total force interaction. It is shown that the b...
Simultaneous non-contact atomic force microscopy (nc-AFM)/STM imaging and force spectroscopy of Si(1 0 0)(2 × 1) with small oscillation amplitudes
Özer, H.Özgür; Atabak, Mehrdad; Ellialtǧlu, Recai M.; Oral, Ahmet (2002-03-28)
Si(1 0 0)(2 x 1) surface is imaged using a new non-contact atomic force microscopy (nc-AFM)/STM with sub-Angstrom oscillation amplitudes using stiff tungsten levers. Simultaneous force gradient and STM images of individual dimers and atomic scale defects are obtained. We measured force-distance (f-d) curves with different tips. Some of the tips show long force interactions, whereas some others resolve short-range interatomic force interactions. We observed that the tips showing short-range force interaction...
Real-time scanning hall probe microscopy
Oral, Ahmet; HENİNİ, M (1996-08-26)
We describe a low-noise scanning Hall probe microscope having unprecedented magnetic field sensitivity (similar to 2.9x10(-8) T/root Hz at 77 K), high spatial resolution, (similar to 0.85 mu m),nd operating in real-time (similar to 1 frame/s) for studying flux profiles at surfaces. A submicron Hall probe manufactured in a GaAs/A1GaAs two-dimensional electron gas (2DEG) is scanned over the sample to measure the surface magnetic fields using conventional scanning tunneling microscopy positioning techniques. F...
Dispersive optical constants of Tl2InGaSe4 single crystals
Qasrawi, A. F.; Hasanlı, Nızamı (IOP Publishing, 2007-09-01)
The structural and optical properties of Bridgman method grown Tl2InGaSe4 crystals have been investigated by means of room temperature x-ray diffraction, and transmittance and reflectance spectral analysis, respectively. The x-ray diffraction technique has shown that Tl2InGaSe4 is a single phase crystal of a monoclinic unit cell that exhibits the lattice parameters of a = 0.77244 nm, b = 0.64945 nm, c = 0.92205 nm and beta = 95.03 degrees . The optical data have revealed an indirect allowed transition band ...
Citation Formats
E. Karagöz, “Non-contact atomic force microscope in ultra high vacuum using radiation pressure excitation of cantilever with Fabry-Perot interferometer,” M.S. - Master of Science, Middle East Technical University, 2017.