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Phys.421 Condensed Matter Physics-II 3+1
LEARNING OBJECTIVES:
The primary aim of this course is to:
This course is designed to teach students the relation between the structure and properties
of exhibited by the crystalline solids.
The details of band theory and effect of periodic potential on energy dispersions of
electron. Role of lattice dynamics in thermal properties of solids.
This course also aim to introduce the students to various typesof properties of materials
such as dielectrics, magnetic and superconducting properties.
LEARNING OUTCOMES:
After reading this course, the students will be able to:
understand how the energy dispersions of the electron are affected when large number of
atoms come together to form crystalline materials.
What is the impact of periodic potential on electronic energy states in a crystal?
What causes the magnetism in any material and how one can explain various type of
magnetic behaviours exhibited different materials.
The students will also be able to understand the dielectric and superconducting materials
and underlying mechanisms to explain their properties.
Pursue the research work in the field of material science and nanotechnology.
THEORY (45 Hours)
UNIT 1 (10 Hours)
Structure of solids: Bravais lattice, primitive vectors, primitive unit cell, conventional unit cell,
Wigner-Seitz cell; Symmetry operations and classification of 2- and 3-dimensional Bravais
lattices; point group and space group (information only); Common crystal structures: NaCl and
CsCl structure, close-packed structure, Zinc blende and Wurtzite structure, tetrahedral and
octahedral interstitial sites, Spinel structure; Intensity of scattered X-ray, Friedel‘s law,
Anomalous scattering; Atomic and geometric structure factors; systematic absences; Reciprocal
lattice and Brillouin zone; Ewald construction; Explanation of experimental methods on the basis
of Ewald construction; Electron and neutron scattering by crystals (qualitative discussion);
Surface crystallography; Graphene; Real space analysis — HRTEM, STM, FIM. Non crystalline
solids-Monatomic amorphous materials; Radial distribution function; Structureof vitreous silica.
UNIT 2 (5 Hours)
Band theory of solids: Bloch equation; Empty lattice band; Number of states in a band; Effective
mass of an electron in a band: concept of holes; Classification of metal, semiconductor and
insulator; Electronic band structures in solids - Nearly free electron bands; Tight binding method -
application to a simple cubic lattice; Band structures in copper, GaAs and silicon; Topology of
Fermi-surface; Quantization of orbits in a magnetic field, cyclotron resonance — de Haas-van
Alphen effect; Boltzmann transport equation - relaxation time approximation, Sommerfeld theory
of electrical conductivity.
UNIT 3 (5 Hours)
Lattice dynamics and Specific heat, Classical theory of lattice vibration under harmonic
approximation; Dispersion relations of one dimension lattices: monatomic and diatomic cases,
Characteristics of different modes, long wavelength limit, Optical properties of ionic crystal in the
infrared region; Inelastic scattering of neutron by phonon; Lattice heat capacity, models of Debye
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