This book is a concise introduction to the key concepts of classical field theory for beginning graduate students and advanced undergraduate students who wish to study the unifying structures and physical insights provided by classical field theory without dealing. According to the classical free electron theory the value of specific heat of metals is given by 4. In 1998 he joined the faculty of the university of hawaii where he is currently an associate professor of physics. Mar, 2017 start free trial sign in engineering physics by s. Free electron theory of metals ppt video online download. The dude model is the application of kinetic theory to electrons in a solid. This theory is called quantum free electron theory. But quantum theory states that only a few electron absorb the supplied energy. Ron ballinger gives todays lecture, explaining how the behavior of electrons in aggregate solids determines their electrical and thermal conductivities, optical absorption, and other physical properties. Ppt on free electron theory free download as powerpoint presentation.
Landaus model is now known as the fermi liquid theory. These features determine the intrinsic orbital angular momentum carried by localized vortex states. He derives the valence and conduction band structures for electrons in metals e. Pdf an electron, in an abrahamlorentzpoincare model, is a uniformly charged spherical shell abraham, 1903, 1904. Digi notes electrical conductivity in materials pdf download rajeev reddy nareddula.
Engineering physics ii unit 1 conducting materials. Engineering physics 1st year book and notes pdf download. Sommerfeld developed this theory during according to this theory, the free electrons obey quantum laws. Classical electron masers and free electron lasers. Dec 03, 2012 for the love of physics walter lewin may 16, 2011 duration. This requires an understanding of the dual waveparticle nature of electrons and in turn quantum mechanics. Waves in relativistic electron beams presents an advanced course of classical electrodynamics with application to the generation of highpower coherent radiation in the microwave to opticalwave regions. Engineering physics vtu notes pdf ep vtu pdf smartzworld. According to this theory the electrons are moving freely and randomly moving in the entire. It was developed in 1927, principally by arnold sommerfeld, who combined the classical drude model.
Motion in one dimension and vectors, motion in two and three dimensions and force and motion, work and kinetic energy, potential energy and conservation of energy, center of mass and linear momentum, rotation, torque and angular momentum, equilibrium and elasticity, gravitation, oscillations, waves and sound. As per his investigation, the behavior of free electron in different possible energy states is explained, how the large number of electrons are disturbed in the energy states. Apr 10, 20 the classical free electron theory ofmetals drude lorentz theory of metals lecture2postulates. Classical free electron theory, derivation of ohms law, mean free path, relaxation time and drift velocity, failures of classical free electron theory, quantum free electron theory, fermidirac distribution, fermi energy, failures of quantum free electron theory. Drawbacks of classical free electron theory 2740332 1. Specifically, it provides readers with the basics of advanced electromagnetic theory and relativistic electrodynamics, guiding them step by step through the theory of freeelectron lasers. The classical electron radius is sometimes known as the lorentz radius or the thomson scattering length. The classical free electron theory was introduced by p. Digi notes electrical conductivity in materials pdf download. Put free electrons into a very wide potential well the same size as. The free electron theory of metals using classical laws was developed by dude and lorentz in the beginning of last century.
A metal is imagined as the structure of 3dimensional array of ions in between which, there are free moving valence electrons confined to the body of. Hence, classical free electron fails to explain the temperature dependence of electrical conductivity. Classical theory states that all free electrons absorb the supplied energy. Ppt on free electron theory electrical resistivity and. The classical free electron theory ofmetals drude lorentz theory of metals lecture2postulates. Classical field theory and the stressenergy tensor book. Postulates of classical free electron theory 1 the free electrons of a metal are having like the moleculesof a gas in acontainer. Page 4 v d while the free electrons move towards the positive terminal in the presence of the.
The free electron model considers that metals are composed of a quantum electron gas where ions play almost no role. Louisell department of physics, university of southern. The valence electrons of atoms are free to move about the whole volume of the metals like the molecules of a perfect gas in a container. It is shown that the traditional conservation laws for total charge, energy, linear and angular momentum, hold jointly in classical electron theory if and only if classical electron spin is included as dynamical degree of freedom. Classical free electron theory of metals in order to explain electrical conductivity in metals, lorentz and drude put forward a theory called free electron theory of metals. Download as ppt, pdf, txt or read online from scribd. Drude and lorentz developed this theory in according to this theory the metals containing free electrons obey the laws of classical mechanics. Atomic selectrons are delocalised due to overlap of outer orbits. A statistical equation for describing the mean drift velocity in the direction of the field may be written. Metals drudes classical theory theory by paul drude in 1900, only three years after the electron was discovered. In 1928, sommerfeld developed a new theory applying quantum mechanical concepts and fermidirac statistics to the free electrons in the metal. This idea was given by drude and he utilized it to explain many properties of metals satisfactorily such as electrical conductivity, thermal conductivity etc. Then sommerfelds elementary quantum mechanical theory of metals is discussed. The photoelectric effect, compton effect and the black body radiation cannot be explained by the classical free electron theory.
Srit unit iii free electron theory applied physics. At its heart quantum mechanics is a mathematically abstract subject expressed in terms of the language of complex linear vector spaces. Engineering physicsii classical free electron theory of. Classical free electron theory electrical conductivity the classical free electron theory was proposed by drude and lorentz. According to classical free electron the electronic specific heat is equal to r 2 3 while the actual value is 0. Engineering physics ii unit 1 conducting materials notes. Here you can download the engineering physics vtu notes pdf ep vtu pdf of as per vtu syllabus.
But in classical free electron theory, it is a constant in all temperature. It was developed in 1927, principally by arnold sommerfeld, who combined the classical drude model with quantum mechanical fermidirac statistics and hence it is also known as the drudesommerfeld model. Quantum free electron theory was proposed by arnold sommerfeld. This textbook focuses on the fully classical theory of fels with application to fel oscillators and develops the fundamentals of fel theory in sufficient depth to provide both a solid understanding of fel physics and a solid background for research in the field. Jun 15, 2018 neglecting the electron electron interaction and the electron ion interaction, it appears as if the electrons move in a confined box with periodic collision with ions in the lattice.
Quantum free electron theory of metals science key. He was a postdoctoral research scientist at the duke free electron laser laboratory from 1992 to 1998, where he made pioneering contributions to the phaselocked and chirpedpulse free electron laser. Free electron theory of metals nicholas research group. In solidstate physics, the free electron model is a simple model for the behaviour of charge. The classical theory fails to explain the heat capacity and the magnetic susceptibility of the conduction electrons. Unit1 classical free electron theory physics youtube. Both classical and quantum waves can form vortices. Give the assumptions of the classical free electron theory. Free electrons in a metal resemble molecules of a gas. For the love of physics walter lewin may 16, 2011 duration. Stimulated radiation of excited classical electron oscillators. According to the classical free electron theory the value of specific heat of metals is. Digi notes electrical conductivity in materials pdf.
According to classical free electron theory of metals electrical conductivity is given by, from the above equation, relation between temperature and electrical conductivity is given by hence, classical free electron fails to explain the temperature dependence of electrical conductivity. Classical theory of freeelectron lasers book iopscience. Resonators of gyromonotrons free and forced oscillations theory of a gyromonotron. Given its simplicity, it is surprisingly successful in.
Quantum theory macro particle classical physics based on newtons laws micro particle quantum physics. You can download free classical free electron theory of metals engineering physics edurev notes pdf from edurev by using search above. The phenomena such a photoelectric effect, compton effect and the black body radiation couldnt be explained by classical free electron theory. Classical free electron theory of metals engineering physics. It is one of a trio of related scales of length, the other two being the bohr radius. Scully department of physics and optical sciences center, university of arizona, tucson, arizona 85721, usa and w. Classical relativistic electrodynamics theory of light. Below we have list all the links as per the modules. What are the drawbacks of classical free electron theory. In solidstate physics, the free electron model is a simple model for the behaviour of. Physics 12, classical free electron theory by patrick bruskiewich. Drude treated the free electrons as a classical ideal gas but the electrons should collide with the stationary ions, not with each other. A classical theory of the electron, proposed by one of us several years ago and based on finitedifference equations, is discussed by considering the three possible following cases.
Spontaneous radiation of classical electron oscillators. Classical free electron theory could not explain many physical properties. Cu, be using lcaomo, and then extends this approach. Classical free electron theory of metals engineering. That time the valance electrons in metals were regarded as the noninteracting particles of an ideal gas. The main assumptions of classical free electron theory are. This book describes how modern physics based on relativity theory and quantum mechanics was born in the beginning of the 20th century from a collapse of classical physics. In an atom electrons revolue around the nucleus and a metal is composed of such atoms. B m s institute of technology classical free electron theory. Dr faustus, zenos paradox, birth of modern physics, the fall of science, mysticism of modern physics, quantum field magics, paradoxes and. To describe the quantum properties of any physical system, a new mathematical language is required as compared to that of classical mechanics. A metal is imagined as the structure of 3dimensional array of ions in between which, there are free moving valence electrons confined to the body of the material. The valence electrons of metallic atoms are free to move in the spaces between ions from one place to another place within the metallic specimen similar to. The classical free electron theory drude and lorentz.
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