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This chapter covers the background to AFM, placing it in the context of other microscopic techniques. It describes some major highlights of AFM, illustrating the power of the technique. It describes how AFM can be compared to optical and electron microscopy, and where AFM is a more suitable technique, and also where it is not. The AFM was developed as a version of the scanning tunnelling microscope (STM), that would be more capable of imaging biological samples; however AFM is now far more widely used than STM, and the chapter describes the development of AFM and STM, and shows why AFM is more popular for many samples.

Scanning probe microscopy (SPM) scans a fine tip close to a surface and measures the tunneling current (STM) or force (SFM), based on many possible tip-surface interactions. STM provides atomic resolution imaging, or the local electronic structure (spectroscopy) as a function of bias voltage, and is also used to manipulate adsorbed atoms on a clean surface. STM operates in two modes— constant current or height—and requires a conducting specimen. SFM uses a cantilever (force sensor) to measure short range (< 1 nm) chemical, and a variety of long-range (< 100 nm) forces, depending on the tip and the specimen; a conducting specimen is not required. In static mode, the tip height is controlled to maintain a constant force, and measure surface topography. In dynamic mode, changes in the vibrational properties of the cantilever are measured using frequency, amplitude, or phase modulation as feedback to control the tip-surface distance and form the image. Dynamic imaging includes contact and non-contact modes, but intermittent contact or tapping mode is common. SPMs measure properties (optical, acoustic, conductance, electrochemical, capacitance, thermal, magnetic, etc.) using appropriate tips, and find applications in the physical and life sciences. They are also used for nanoscale lithography.

Nanoscale scientific research suddenly arose during the 1980s and 1990s. It now constitutes an immense worldwide research domain. It is based on the invention of scanning probe microscopy and powerful numerical simulation, and on the capacity to manipulate individual molecules and atoms. The capacity of nanoscale research to synthesize artificial substances, often through epitaxy, such as fullerenes and low-dimensional objects, has fueled important transformations in scientific investigation and allowed the formulation of previously unimagined questions. The emergence of nanostructured materials and corresponding instrumentation has been fueled by cognitive, methodological, instrumental, and material combinatorials. “Combinatorial” refers to an association or interlocking of two or more components that give rise to a resulting novelty in the form of a synergy.

Polymer devices for electronic applications are generally prepared in thin film form and so the effect of surfaces is of significant interest. This chapter covers the thermodynamics of surfaces; different means of preparing thin films of relevance to polymer electronics; and the measurement of surfaces using scanning probe techniques or photoelectron analysis. In the latter case, the use of surface techniques to obtain information on the electronic properties of the material is discussed.

This chapter explains that the field of domain wall (DW) nanoelectronics is predicated on the premise that the distinct physical properties of domain walls offer new conceptual possibilities for devices. It first deals with basic physics of domain wall properties, and in particular the cross-coupling that allows domain walls to display properties and order parameters different from those of the parent bulk material. The chapter then turns to scanning probe techniques for measuring some of these domain wall properties, and specifically atomic force microscopy (AFM). Together with transmission electron microscopy, AFM is one of the most important tools currently available to probe and manipulate the individual position and physical properties of domain walls. Finally, the chapter focuses on two recent developments that allow investigating hitherto overlooked properties of domain walls: their magnetotransport and their mechanical response.

Polymer science is, of course, driven by the desire to produce new materials for new applications. The success of materials such as polyethylene, polypropylene, and polystyrene is such that these materials are manufactured on a huge scale and are indeed ubiquitous. There is still a massive drive to understand these materials and improve their properties in order to meet material requirements; however, increasingly polymers are being applied to a wide range of problems, and certainly in terms of developing new materials there is much more emphasis on control. Such control can be control of molecular weight, for example, the production of polymers with a highly narrow molecular weight distribution by anionic polymerization. The control of polymer architecture extends from block copolymers to other novel architectures such as ladder polymers and dendrimers. Cyclic systems can also be prepared, usually these are lower molecular weight systems, although these also might be expected to be the natural consequence of step-growth polymerization at high conversion. Polymers are used in a wide range of applications, as coatings, as adhesives, as engineering and structural materials, for packaging, and for clothing to name a few. A key feature of the success and versatility of these materials is that it is possible to build in properties by careful design of the (largely) organic molecules from which the chains are built up. For example, rigid aromatic molecules can be used to make high-strength fibres, the most highprofile example of this being Kevlar®; rigid molecules of this type are often made by simple step-growth polymerization and offer particular synthetic challenges as outlined in Chapter 4. There is now an increasing demand for highly specialized materials for use in for example optical and electronic applications and polymers have been singled out as having particular potential in this regard. For example, there is considerable interest in the development of polymers with targeted optical properties such as second-order optical nonlinearity, and in conducting polymers as electrode materials, as a route towards supercapacitors and as electroluminescent materials. Polymeric materials can also be used as an electrolyte in the design of compact batteries.

The experimental and theoretical characterization of oxide nanostructures is addressed. The experimental techniques are classified according to their information content, revealing atomic geometry, chemical composition, electronic structure as well as magnetic, vibrational and chemical properties. Due to the nanometer scale dimensions of oxide nanosystems, many experimental techniques are derived fom the field of surface science and involve ultrahigh vacuum technology. The quantum-theoretical simulations for the description of oxide materials are presented by progressing from simple to increasingly sophisticated methods; the latter become necessary to accurately treat electron correlation effects, which are significant in many oxide materials, in particular at low dimension. Electronic structure methods, total energy methods and atomic structure simulation methods are introduced and discussed.