Research Information System
Thesis Type: Postgraduate
Institution Of The Thesis: Orta Doğu Teknik Üniversitesi, Faculty of Arts and Sciences, Department of Physics, Turkey
Approval Date: 2017
Student: ERCAN KARAGÖZ
Supervisor: AHMET ORAL
Abstract: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.