Open Access

Franz Josef Gießibl

• The essence of the work presented here is the introduction, the advance in theoretical understanding and the practical improvement of frequency-modulation AFM as a viable technique that enriches the toolset of surface scientists. In the course of this work, true atomic resolution by AFM on a reactive surface has been demonstrated for the first time, the theoretical understanding of the origin of frequency shifts in FMAFM has been advanced, the theoretical comprehension of the instrumental noise limit has been extended, an easy-to-use force sensor with unprecedented resolution has been introduced and subatomic features of an atom have been observed for the first time in real space. This text is structured in the following fashion: Chapter 2 contains a brief review of STM with a discussion of the driving factors which are the basis for the spatial resolution of STM and a comparison with the AFM. Chapter 3 summarizes the extra challenges which are faced by AFM in addition to theThe essence of the work presented here is the introduction, the advance in theoretical understanding and the practical improvement of frequency-modulation AFM as a viable technique that enriches the toolset of surface scientists. In the course of this work, true atomic resolution by AFM on a reactive surface has been demonstrated for the first time, the theoretical understanding of the origin of frequency shifts in FMAFM has been advanced, the theoretical comprehension of the instrumental noise limit has been extended, an easy-to-use force sensor with unprecedented resolution has been introduced and subatomic features of an atom have been observed for the first time in real space. This text is structured in the following fashion: Chapter 2 contains a brief review of STM with a discussion of the driving factors which are the basis for the spatial resolution of STM and a comparison with the AFM. Chapter 3 summarizes the extra challenges which are faced by AFM in addition to the conditions for the successful operation of an STM. Chapter 4 describes the experimental implementation of FMAFM in detail. Chapter 5 shows the calculation of the imaging signal, the frequency shift, as a function of the tip-sample forces and chapter 6 contains a calculation of the vertical noise as a function of the operating parameters. A new force sensor with properties which are close to the optimal sensor properties calculated in chapter 6 is described in chapter 7. A summary and outlook is given in chapter 8.…