Preface

With the advent of the atomic force microscope (AFM) came an extremely valuable analytical resource and technique, useful for the qualitative and quantitative surface analysis with sub-nanometer resolution. In addition, samples studied with an AFM do not require any special pretreatments that may alter or damage the sample, and permit a three dimensional investigation of the surface.

This book presents a collection of current research from scientists throughout the world who employ atomic force microscopy in their investigations. The technique has become widely accepted and used in obtaining valuable data in a wide variety of fields. It is impressive to see how it has proliferated and found many uses throughout manufacturing, research and development in the short time period since its development in 1986

The chapter list is given below, along with a brief description, intended to provide insight into their content.

#### *Chapter 1. Crystal Lattice Imaging Using Atomic Force Microscopy*

This book commences by introducing the reader to the crystal lattice imaging that is envisaged and feasible through atomic force microscopy. An instructive introduction to obtaining images with atomic resolution is presented by the author, along with the pitfalls that can be encountered and how to overcome them.

#### *Chapter 2. Atomic Force Microscopy in Optical Imaging and Characterization*

In this chapter, cantilever tips are demonstrated to act effectively as near-field probes, combining optical measurements with the high lateral resolution of AFM. The authors demonstrate that nanostructures of 10 nm can be resolved independent of illumination wavelength.

#### *Chapter 3. Magnetic Force Microscopy: Basic Principles and Applications*

This chapter introduces the reader to magnetic force microscopy, which is derived from AFM and is useful for imaging magnetization patterns with high resolution. The image is obtained by the magnetic force interaction between the tip and sample

#### XII Preface

surface. The authors also present MFM analysis of the magnetic properties of Si and Ge-based magnetic semiconductors.

Preface XI

**Victor Bellitto** 

USA

Naval Surface Warfare Center

*Chapter 9. AFM Application in III-nitride Materials and Devices*

*Materials*

original properties.

and temperature changes.

Acknowledgments

researchers.

The application of atomic force microscopy in GaN, In(Ga)N and Al(Ga)N film growth and devices is reviewed in this chapter. The authors demonstrate how surface morphology and dislocations affect film growth, device performance and processing.

*Chapter 10. Atomic Force Microscopy to Characterize the Healing Potential of Asphaltic* 

In this chapter, atomic force microscopy is applied to the study of asphaltic materials, to overcome limitations incurred by the opacity of the material and its adhesive properties. The authors, through the use of atomic force microscopy, demonstrate and develop a model of the physico-chemical "healing" or restoration of bitumen to its

*Chapter 11. Atomic Force Microscopy-for investigating surface treatment of textile fibres*

This chapter demonstrates the use of Lateral force microscopy combined with an electronic microbalance to characterize frictional properties of sized and desized glass fibers. The authors also use atomic force microscopy to study surface morphological changes to a PET fabric surface, following plasma treatments, aging, light exposure

I would like to recognize the authors of the chapters for their tremendous contributions in their areas of expertise. I would also like to express my thanks to them for their time and efforts that have been invested in the publication of their work. The information and knowledge captured in this book will certainly benefit other

#### *Chapter 4. Vibration Responses of Atomic Force Microscope Cantilevers*

During the sampling process in AFM, it is necessary to accurately calculate the vibrational response of the cantilever. In this chapter, the flexural vibration responses of the cantilever are evaluated using the Timoshenko beam theory and the model superposition method. The authors demonstrate that when the ratio of the Young's modulus to shear modulus is greater than 1000, the Timoshenko beam model is better suited for simulating the flexural vibration response of an AFM cantilever.

#### *Chapter 5. Wavelet Transforms in Dynamic Atomic Force Spectroscopy*

In this chapter, an introduction to wavelet transforms is provided, which allow a reduction in the acquisition time to values comparable with dynamic force spectroscopy imaging. The authors propose the technique of wavelet analysis to detect transient spectral features in a time domain of tens of milliseconds, to enable real time analysis of surface chemical kinetics or surface force modification with dynamic force spectroscopy.

#### *Chapter 6. Nanoscale Effects of Friction, Adhesion and Electrical Conduction in AFM Experiments.*

This chapter provides an introduction to nanotribology, a field of tribology that studies the interactions between contacting surfaces in relative motion at the atomicand nano-scale. The author presents the combination techniques of AFM and point contact microscopy (PCM), where electrical current through the point-contact of the AFM tip is used to reveal the atomic scale periodicity of the substrate.

#### *Chapter 7. Measurement of the Nanoscale Roughness by Atomic Force Microscopy: Basic Principles and Magnetic Force Microscopy: Basic Principles and Applications*

The various surface roughness measurements that can be performed with atomic force microscopy are described and discussed, along with the different applications of surface roughness in material characterization. The authors also introduce fractal dimension and power spectral density as complementary techniques to surface roughness analysis.

#### *Chapter 8. Predicting Macroscale Effects through Nanoscale Features*

This chapter demonstrates how a large enough data set of surface characteristics can be acquired by atomic force microscopy to conduct statistical analysis and investigate the behavior of materials at the macroscale. The authors also demonstrate that, aided by regression techniques, the relationship between nanoscale features and the macroscale behavior can be precisely estimated.

#### *Chapter 9. AFM Application in III-nitride Materials and Devices*

The application of atomic force microscopy in GaN, In(Ga)N and Al(Ga)N film growth and devices is reviewed in this chapter. The authors demonstrate how surface morphology and dislocations affect film growth, device performance and processing.

#### *Chapter 10. Atomic Force Microscopy to Characterize the Healing Potential of Asphaltic Materials*

In this chapter, atomic force microscopy is applied to the study of asphaltic materials, to overcome limitations incurred by the opacity of the material and its adhesive properties. The authors, through the use of atomic force microscopy, demonstrate and develop a model of the physico-chemical "healing" or restoration of bitumen to its original properties.

#### *Chapter 11. Atomic Force Microscopy-for investigating surface treatment of textile fibres*

This chapter demonstrates the use of Lateral force microscopy combined with an electronic microbalance to characterize frictional properties of sized and desized glass fibers. The authors also use atomic force microscopy to study surface morphological changes to a PET fabric surface, following plasma treatments, aging, light exposure and temperature changes.

#### Acknowledgments

X Preface

Ge-based magnetic semiconductors.

dynamic force spectroscopy.

*Experiments.*

roughness analysis.

surface. The authors also present MFM analysis of the magnetic properties of Si and

During the sampling process in AFM, it is necessary to accurately calculate the vibrational response of the cantilever. In this chapter, the flexural vibration responses of the cantilever are evaluated using the Timoshenko beam theory and the model superposition method. The authors demonstrate that when the ratio of the Young's modulus to shear modulus is greater than 1000, the Timoshenko beam model is better

In this chapter, an introduction to wavelet transforms is provided, which allow a reduction in the acquisition time to values comparable with dynamic force spectroscopy imaging. The authors propose the technique of wavelet analysis to detect transient spectral features in a time domain of tens of milliseconds, to enable real time analysis of surface chemical kinetics or surface force modification with

*Chapter 6. Nanoscale Effects of Friction, Adhesion and Electrical Conduction in AFM*

This chapter provides an introduction to nanotribology, a field of tribology that studies the interactions between contacting surfaces in relative motion at the atomicand nano-scale. The author presents the combination techniques of AFM and point contact microscopy (PCM), where electrical current through the point-contact of the

*Chapter 7. Measurement of the Nanoscale Roughness by Atomic Force Microscopy: Basic* 

The various surface roughness measurements that can be performed with atomic force microscopy are described and discussed, along with the different applications of surface roughness in material characterization. The authors also introduce fractal dimension and power spectral density as complementary techniques to surface

This chapter demonstrates how a large enough data set of surface characteristics can be acquired by atomic force microscopy to conduct statistical analysis and investigate the behavior of materials at the macroscale. The authors also demonstrate that, aided by regression techniques, the relationship between nanoscale features and the

AFM tip is used to reveal the atomic scale periodicity of the substrate.

*Principles and Magnetic Force Microscopy: Basic Principles and Applications*

*Chapter 8. Predicting Macroscale Effects through Nanoscale Features*

macroscale behavior can be precisely estimated.

*Chapter 4. Vibration Responses of Atomic Force Microscope Cantilevers*

*Chapter 5. Wavelet Transforms in Dynamic Atomic Force Spectroscopy*

suited for simulating the flexural vibration response of an AFM cantilever.

I would like to recognize the authors of the chapters for their tremendous contributions in their areas of expertise. I would also like to express my thanks to them for their time and efforts that have been invested in the publication of their work. The information and knowledge captured in this book will certainly benefit other researchers.

> **Victor Bellitto**  Naval Surface Warfare Center USA

**1** 

Vishal Gupta

*USA* 

*FLSmidth Salt Lake City Inc.* 

**Crystal Lattice Imaging Using** 

Atomic force microscopy (AFM) has been a very useful tool in interrogating the micron-tonano sized structures at both atomic and subnanometer resolution. AFM allows both imaging of surfaces and interactions with surfaces of interest to help researchers explain the crystal lattice structure, and surface chemical and mechanical properties at nano scale. Since the invention of AFM, one has been frequently attracted by AFM images when browsing through many scientific publications in physics, chemistry, materials, geology, and biology (Gan, 2009; Sokolov *et al.*, 1999; Wicks *et al.*, 1994). AFM has been successfully used for imaging solid surfaces with subnanometer resolution for natural materials such as minerals, synthetic materials such as polymers and ceramics, and biological materials such as live organisms. There are also numerous reports of molecular and subnanometer resolution on

Atomic force microscopy (AFM) has been quite successfully used by scientists and researchers in obtaining the atomic resolution images of mineral surfaces. It is quite amazing to see the individual atoms, and their arrangements, that make up the surfaces. In some cases, atoms from the mineral surfaces can be deliberately removed with the AFM so that

The key to obtaining atomic-scale imaging is precisely control the interactions between the atoms of the scanning tip and the atoms of the surface being studied. Ideally a single atom of the tip is attracted or repelled by successive atoms of the surface being studied. However, this is a dynamic environment and there can be accidental or deliberate wear of the tip and the surface, so the situation is far from ideal. A number of theoretical and practical studies have added some understanding of this interaction but our understanding is still incomplete (Nagy, 1994). Despite the imperfect knowledge, application of the instrument to mineral

It is now well established with some success that AFM can also be used to investigate the crystal lattice structure of mineral surfaces. Atomic resolution has been successfully obtained on graphite (Albrecht & Quate, 1988; Sugawara *et al.*, 1991), molybdenum sulfide (Albrecht & Quate, 1988), boron nitride (Albrecht & Quate, 1987), germanium (Gould *et al.*, 1990), sapphire (Gan *et al.*, 2007), albite (Drake & Hellmann, 1991), calcite (Ohnesorge & Binnig, 1993) and sodium chloride (Meyer & Amer, 1990). The AFM has also been used to

studies demonstrates that the AFM works well, often at atomic scale resolution.

**1. Introduction** 

biological and polymer samples.

the internal structure of the surface can be studied.

**Atomic Force Microscopy** 
