Theoretical Assessment of the Mechanical, Electronic, and Vibrational Properties of the Paramagnetic Insulating Cerium Dioxide and Investigation of Intrinsic Defects

First-principles calculations are performed by taking into account the strong correlation effects on ceria. To obtain an accurate description including f electrons, the authors optimized the Coulomb U parameter for use in Local-Density Approximation (LDA) and Generalized Gradient Approximation (GGA) calculation. A good agreement with experimental data is obtained within the GGA+U (Wu-Cohen scheme). Elastic stiffness constants are found in correct agreement with the available experimental results. Born effective charge, dielectric permittivity, and the phonon-dispersion curves are computed using density functional perturbation theory. The origin of magnetism in undoped ceria with intrinsic defects is investigated. The authors show that both of Ce and O vacancies induce local moments and ferromagnetism without doping ceria by magnetic impurities in this chapter.

Conductive Probe Microscopy Investigation of Electrical and Charge Transport in Advanced Carbon Nanotubes and Nanofibers-Polymer Nanocomposites

In this chapter, the main scanning probe microscopy-based methods to measure the transport properties in advanced polymer-Carbon Nanotubes (CNT) nanocomposites are presented. The two major approaches to investigate the electrical and charge transport (i.e., Electrostatic Force Microscopy [EFM] and Current-Sensing Atomic Force Microscopy [CS-AFM]) are illustrated, starting from their basic principles. First, the authors show how the EFM-related techniques can be used to provide, at high spatial resolution, a three-dimensional representation CNT networks underneath the surface. This allows the studying of the role of nanoscopic features such as CNTs, CNT-CNT direct contact, and polymer-CNT junctions in determining the overall composite properties. Complementary, CS-AFM can bring insight into the transport mechanism by imaging the spatial distribution of currents percolation paths within the nanocomposite. Finally, the authors show how the CS-AFM can be used to quantify the surface/bulk percolation probability and the nanoscopic electrical conductivity, which allows one to predict the macroscopic percolation model.

Nano Indentation Response of Various Thin Films Used for Tribological Applications

Various thin films used for tribological applications are classified under four heads. Based on their load vs. displacement curves, which have some characteristics features, the ratio of nanohardness to elastic modulus and the ratio of cube of nanohardness to square of elastic modulus are evaluated in this chapter. It is demonstrated that depending on the type of film used, these ratios vary within a certain range. For soft self-lubricating films, these ratios are very low; whereas for hard self-lubricating film, these ratios are quite high.

Understanding the Numerical Resolution of Perturbed Soliton Propagation in Single Mode Optical Fiber

The authors solve the propagation soliton perturbation problem in a nonlinear optical system based on a single mode optical fiber by introducing Rayleigh's dissipation function in the framework of variational approach. The adopted methodology has facilitated the variational approach to be applied on a dissipative system where the Lagrangian and Hamiltonian are difficult to solve. The authors model the propagation in a nonlinear medium by using a nonlinear Schrödinger equation (NLSE). This is a mathematical model used to describe the optical fiber. The chapter is focused on the propagation of perturbed solitary waves in single mode fiber.

Applications of Nanomaterials in Construction Industry

The application of nanomaterials in various applied fields has gained worldwide recognition. Nanomaterials have the ability to manipulate the structure at nano-scale. This leads to the generation of tailored and multifunctional composites with improved mechanical and durability performance. Recognizing this, the construction industry recently has started to use a variety of nanomaterials. The use of these materials is found to improve various fundamental characteristics of construction materials including the strength, durability, and lightness. In this chapter an attempt is made to review the use of various nanomaterials in cementitous system. This is followed by a discussion of the challenges related to their use. Finally, the strategies for using nanomaterials in construction industry for the next ten years are identified.

Synthesis and Characterization of Iron Oxide Nanoparticles

Iron oxide nanoparticles show great promise in bio-applications like drug delivery, magnetic resonance imaging, and hyperthermia. This is because the size of these magnetic nanoparticles is comparable to biomolecules and the particles can be removed via normal iron metabolic pathways. These nanoparticles are also attractive for industrial separations and catalysis because they can be magnetically recovered. However, the size, morphology, and surface coating of the iron oxide nanoparticles greatly affect their magnetic properties and biocompatibility. Therefore, nanoparticles with tunable characteristics are desirable. This chapter elaborates the synthesis techniques for the formation of iron oxide nanoparticles with good control over reproducibility, surface and magnetic properties, and morphology. The well-known co-precipitation and thermal decomposition methods are detailed in this chapter. The surface modification routes and characterization of these nanoparticles are also discussed. The chapter will be particularly useful for engineering/science graduate students and/or faculty interested in synthesizing iron oxide nanoparticles for specific research applications.

Carbon Nanotubes for Photovoltaics

Recent developments show that the exceptional physical, optical, and electrical properties of Carbon Nanotubes (CNTs) have now caught the attention of the Photovoltaics (PV) industry. This chapter provides an updated and in-depth review of some of the most exciting and important developments in the application of CNTs in photovoltaics. The chapter begins with a discussion of the underlying properties of CNTs that make them promising for PV applications. A review of the literature on the application of CNTs in the photoactive layer of Silicon (Si)-based heterojunctions, as anchors for light harvesting materials in Dye Sensitized Solar Cells (DSSCs) and as components of other organic solar cells (OPVs), is then presented. Findings portend the promise of CNTs in bridging the gap between the two classes of solar cells currently in the market. Since the technology is in its early stages, it is generally limited by a general lack of understanding of CNTs and their adequate growth mechanisms.

In2X3 (X=S, Se, Te) Semiconductor Thin Films

Indium chalcogenide thin film semiconductor compounds In2X3 (with X being a chalcogen atom, i.e., S, Se, or Te) are important materials in many current technological applications such as solar cells, micro-batteries, memory devices, etc. This chapter reviews the recent progress in In2X3 (X = S, Se, or Te) thin film research and development, with a particular attention paid to their growth and processing methods and parameters, and the effects that these have on the films microstructure. The intimate relationship between their fabrication conditions and the resulting physico-chemical and functional properties is discussed. Finally, results pertaining to the fabrication and characterization of these thin film materials, as well as the main devices and applications based on them are also highlighted and discussed in this chapter.

Functionalization of Carbon Nanocomposites with Ruthenium Bipyridine and Terpyridine Complex

Ruthenium bipyridine or terpyridine complexes functionalized carbon-based nanocomposites have special properties in the electromagnetic and photochemical research field. The aims of this chapter include development of functionalized fullerene, carbon nanotubes, and graphene with ruthenium complex and characterization of their nanostructural properties. Such nanocomposites can be accomplished using either covalent or non-covalent functionalization methods.

Silicon Nanostructures-Graphene Nanocomposites

Global demand of energy is increasing at an alarming rate, and nanotechnology is being looked at as a potential solution to meet this challenge (Holtren, 2007). Although the efficiency of energy conversion and storage devices depends on a variety of factors, the overall performance strongly relies on the structure and properties of the component materials (Whitesides, 2007). Compared to conventional materials, silicon (Si) nanostructures and graphene nanosheets possess unique properties (i.e. morphological, electrical, optical, and mechanical) useful for enhancing the energy-conversion and storage performances. Graphene can enhance efficiency of nano-Si based solar cells and battery due to its high electronic conductivity, ultrahigh mobility, high transparency, and strong mechanical property. This chapter provides a comprehensive review of recent progress and material challenges in energy conversion (solar cells) and storage (batteries/supercapacitors) with specific focus on composites of Si nanostructures-graphene nanosheets.