Properties of Electronic Materials

Hummel R 1985 Electronic Properties of Materials (New York Springer)... 

Material Properties Bibhographic Data Purdue University Purdue University (CINDAS) thermophysical, mechanical, and electronic properties of materials bibhographic references and author iadex... 

Though in this paper we have used the relativistic KKR wave functions ets betsis functions, the present approach may be easUy realized within any existing method for calculating the electron states. This will allow the electronic properties of materials with complex magnetic structure to be readily calculated without loss of accuracy. The present technique, being most eflicient for the SDW-type systems, can be also used for helical magnetic structures. In the latter case, however, the spin-polarizing part of potential (18) should be appropriately re-defined. 

In solid state physics, the sensitivity of the EELS spectrum to the density of unoccupied states, reflected in the near-edge fine structure, makes it possible to study bonding, local coordination and local electronic properties of materials. One recent trend in ATEM is to compare ELNES data quantitatively with the results of band structure calculations. Furthermore, the ELNES data can directly be compared to X-ray absorption near edge structures (XANES) or to data obtained with other spectroscopic techniques. However, TEM offers by far the highest spatial resolution in the study of the densities of states (DOS). 

The ECM has been frequently used to study the electronic properties of materials with ionic or partially ionic bonding like in metal oxides. There are many procedures to couple the quantum cluster to its environment, they have been reviewed by Sousa et al. [45]. All these methods have three points in common ... 

Hummel, R. E. Electronic Properties of Materials, 3rd ed. Springer, New York, 2001. Hummel, R. E. Differential reflectance spectroscopy in analysis of surfaces, in R. A. 

As shown in Figure 1.2a, the general trend in the periodic table is for the ionization energy to increase from bottom to top and from left to right (why ). A quantity related to the IE is the work junction. The work function is the energy necessary to remove an electron from the metal surface in thermoelectric or photoelectric emission. We will describe this in more detail in conjunction with electronic properties of materials in Chapter 6. 

The band theory of solids has been developed to account for the electronic properties of materials. Two distinct lines of approach will be described. 

As originally observed by Hertz and later explained by Einstein, electron emission occurs when photons with energy greater than a material s work function irradiate it. The application of this phenomenon led to the development of photoelectron spectroscopy (PES), which is one of the principal methods used to understand chemical and electronic properties of materials. Over the last 40 years advances in technology have also made it possible to determine the spin of the electron and advances in this area have been summarized in several books and reviews [24-28]. A detailed discussion of spin-resolved PES is beyond the scope of this review. The following presents the rudimentary concepts and some illustrative examples. 

Profound changes may occur in the electronic properties of materials as their characteristic length scale is reduced to the nanoscale. These changes affect the optical properties, mechanical response, adsorption behavior, and catalytic properties of the material. 

The reader may justifiably wonder at this point, as to the reasons why Al interconnection were not replaced by Cu ones much earlier. The reason was that copper metal from the interconnection could readily diffuse into the semi-conductor, interfering with (changing) the electronic properties of material. This now can be avoided with the development of new effective diffusion barriers. 

R. E. Hummel, Electronic Properties of Materials, Springer-Verlag, Berlin, 1985. 

Twin boundaries are boundaries in a crystal in which the crystal matrix on one side of the boundary mirrors the crystal matrix on the other (Figure 3.24c). The mirror plane, or twin plane, may not be identical to the plane along which the two mirror-related parts of the crystal join, which is called the composition plane. Twin boundaries affect mechanical, optical and electronic properties of materials in a similar way to grain boundaries. 

R.E. Hummel, 2001, Electronic Properties of Materials 3rd edn. Springer, New York. 

Hummel, R., Electronic properties of materials, New York, Springer-Verlag, 1985. 

The real band structure of a material is actually a complex three-dimensional shape. Even so these simple representations can be used to illustrate many of the important electronic properties of materials. When is zero, as in the case of most metals, there are free electrons... 

Hummel, R. E. Electronic Properties of Materials 2nd ed. Springer New York, 1993. 

The Born-Oppenheimer Hamiltonian is widely used in solid state physics and quantum chemistry to study the electronic properties of materials - and it is also widely used in this book. In the next section we recast it in the very convenient second quantization representation. 

The characteristics of energy states at or near the Fermi energy determine many electronic properties of materials. In order that electrons contribute to the electrical conductivity, for example, it is necessary that there be unoccupied electronic states at energies close to the occupied... 

With the surge in research on carbonaceous nanomaterials, the combination of these entities with metal oxide nanoparticles is enticing as the electronic properties of materials such as graphene may influence particle characteristics. For this reason, the interaction of titania nanoparticles with B- and N-doped graphene has been investigated recently in order to study the photodegradation of dye molecules by these composites. Anatase Ti02... 

Finite size effects play a central role in dictating the electronic properties of materials at the nanoscale. Due to their unique electronic structure, quasi-zero-dimensional (quantum dots) graphitic structures may exhibit fascinating physical phenomena, which are absent in their quasi-one-dimensional (nanowires, nanotubes, and nanoribbons) coimterparts. Many factors govern the effect of reduced dimensions on the electronic properties of nanoscale materials. Here we focus on two such important factors, which are strongly manifested in the electronic characteristics of graphitic materials, namely, quantum confinement and edge effects ... 

Most readers are probably familiar with the Bragg formula for x-ray diffraction (XRD), 2d sin 6 = nX, and the selection rules that tell us that the sum of the Miller indices for body-centered cubic (bcc) crystals must be even and the indices for face-centered cubic (fee) crystals must be all even or all odd in order to produce a diffraction peak. The intent of this chapter is to give a more general derivation of the Laue conditions leading to Bragg reflections of electrons and phonons that take place in three-dimensional (3D) crystals. These reflections from lattice planes within the crystal are fimdamental to the imderstand-ing of the thermal and electronic properties of materials. In the process, the reciprocal lattice will be introduced which will be widely used in subsequent chapters to describe how materials behave thermally, electronically, magnetically, and photonically. 

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