Читать книгу Introduction to Solid State Physics for Materials Engineers - Emil Zolotoyabko - Страница 11

If we consider a crystalline state, the quintessence of solid state physics is the propagation of electron waves and acoustic waves (phonons) in a medium with translational symmetry and further interaction of electrons with phonons and photons, as well as an interaction between electrons themselves. This statement determines the structure of the present book.

The book starts with a discussion of the general impact of translational symmetry in crystals on solid state physics (Chapter 1) and includes a brief description of crystal symmetry in real space; the interrelation between symmetry and physical properties in crystals; wave propagation in periodic media and construction of reciprocal lattices; and qualitative considerations regarding the diffraction of valence electrons on periodic lattice potential and band gap formation.

In Chapter 2, the band gap formation at the Brillouin zone boundary is quantitatively treated by solving the Schrödinger equation in periodic medium. In addition, the structure of energy bands in metals, semiconductors, and insulators is considered, including some aspects of orbital hybridization and the band structure of graphene. At the end of this chapter we discuss the concept of a Fermi surface, its measurement by different methods and its connection to electron conduction.

Chapter 3 is devoted to elastic wave propagation in crystals and includes definitions of acoustic and optical phonons, and a description of the thermal properties of crystals. Here we introduce Debye temperature and Bose–Einstein statistics. Additionally, we show how to calculate the velocities of bulk acoustic waves and surface (Rayleigh) acoustic waves.

In Chapter 4, we deal with electrical conductivity in metals in the framework of classical Drude theory and performing quantum–mechanical calculations. Contributions to metal resistivity from electron scattering by phonons and lattice defects are thoroughly analyzed. Here we introduce Fermi–Dirac statistics and establish the interrelation between Fermi energy and chemical potential.

In Chapter 5, we consider the electron contribution to thermal properties of crystals: electronic specific heat and the electronic part of thermal conductivity. We also discuss the interrelation between electrical conductivity and thermal conductivity in metals, which leads to the Wiedemann–Franz law. The rest of the chapter is devoted to thermoelectricity, i.e. the Seebeck, Peltier, and Thomson effects, and thermoelectric materials with a high figure of merit.

Chapter 6 is devoted to electrical conductivity via electrons and holes in intrinsic (undoped) and doped semiconductors. In this chapter the p–n junction concept is introduced and the key phenomenon of band bending in the depletion region is analytically derived. Further, the working principles of semiconductor diodes and transistors are described, including the metal-oxide-semiconductor field-effect transistor (MOSFET).

Chapter 7 is dedicated to contact phenomena arising at the boundary between a metal and a vacuum, as well as at the metal–semiconductor junctions (Schottky contacts). We introduce the important concept of work function and describe methods to measure it by a Kelvin probe, the photoelectric effect or angle-resolved photoemission spectroscopy (APRES). After that, thermionic emission at elevated temperatures and under electric field application is comprehensively treated, bearing in mind the upmost importance of the latter for an invention of field-emission gun.

In Chapters 8 and 9, we discuss light (photon) interaction with materials. In Chapter 8, we describe some key issues regarding this in metals and insulators. Among them are skin effect, light reflection from metal surfaces, plasma frequency, metamaterials, and structural colors. In Chapter 9, we discuss light interaction with semiconductors. Particular topics include photovoltaics, solar cells, solid state radiation detectors, charge-coupled device (CCD), light-emitting diodes, semiconductor lasers, and photonic materials.

The last four chapters are dedicated to cooperative (correlated) phenomena in electron and ion systems. For example, in Chapter 10, we consider superconductivity. The discussed issues include: Cooper pair formation, isotope effect, Giaever tunneling and the Josephson effect, the Meissner effect, superconductors of type I and type II, superconducting magnets, the superconducting quantum interference device (SQUID), and high temperature superconductivity.

Chapter 11 is devoted to ferromagnetism. Sub-subjects comprise determination of atomic magnetic moments, paramagnetism and diamagnetism, the Weiss molecular field, spontaneous magnetization, exchange interaction, the Ising model, magnetic structures, the subdivision of magnetic materials into ferromagnetics, antiferromagnetics and ferrimagnetics, magnetic domains and domain walls, and giant magnetoresistance.

Chapter 12 is called “Ferroelectricity as cooperative phenomenon.” Here we discuss the following issues: ferroelectric crystals, ferroelectric phase transitions in the framework of Landau–Ginzburg theory, dielectric permittivity near the Curie temperature, ferroelectric domains and domain walls, piezoelectric effect in ferroelectrics, and ferroelectrics-based devices.

Other examples of cooperative phenomena in electron systems are given in Chapter 13. They include metal–insulator (Mott) transition and quantum Hall effects: integer and fractional, and topological insulators.