Department of Physics, Unit Catalogue 2007/08 |
PH20063 Condensed matter physics 1 [WL] |
| Credits: 6 |
| Level: Intermediate |
| Semester: 2 |
| Assessment: EX 85%, PR 15% |
| Requisites: |
| Before taking this unit you must take PH10007 and take PH10008 and take PH10053 and take PH20067 |
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Aims: The aims of this unit are to introduce students to the basic ideas that underlie solid state physics, with emphasis on the behaviour of electrons in crystalline structures, particularly in materials that are metallic or semiconducting.
Learning Outcomes: After taking this unit the student should be able to: * apply knowledge of how crystalline structures vibrate and the associated theories of heat capacity; * discuss why it is that classical theories fail and why electrons in solids have to be treated as quantum mechanical waves; * explain the concept of density of states; * describe how allowed and forbidden energy bands arise as a result of crystal potentials and how the properties of electrons in allowed energy bands determine the electrical and optical behaviour; * appreciate the difference between metals, semiconductors and insulators; * discuss the factors that control the electrical conductivity of metals and semiconductors; * know the ways in which crystal structures are described formally and relate structures in real space to those in reciprocal space; * describe how the diffraction of X-rays and of neutrons is related to the properties of the reciprocal lattice; * conduct short experiments on various topics, record details of experimental method and results to an appropriate standard, and write a scientific report displaying an appropriate standard of presentation, style, structure, attention to detail and analysis. Skills: Written Communication T/F A, Numeracy T/F A, Data Acquisition, Handling, and Analysis T/F A, Information Technology T/F A, Problem Solving T/F A, Working as part of a group T/F, Practical laboratory skills T/F A. Content: Free electron models (5 hours): The classical free electron theory and the failure of classical physics. The quantum free electron theory (electrons as waves). The basic properties of metals; density of states and the Fermi sphere. The Hall effect. Electronic structure of solids (7 hours): The effect of crystalline structure on electron behaviour. Introduction of momentum (k) space. The distinction between metals, semiconductors and insulators. Energy bands and effective masses. Electrons and holes. Basic properties of semiconductors; the effects of doping, donors and acceptors. Vibrations of crystal structures (5 hours): Optical and acoustic modes. Phonons. Heat capacity and the further failure of classical physics. The Einstein and Debye models. Basic crystal structures (5 hours): Translational symmetry; space lattices, unit cells, Miller indices. Diffraction of waves in crystalline structures; Bragg law, the reciprocal lattice and Brillouin zones. X-ray and neutron diffraction studies of crystal structures. Laboratory: Performance of experiments designed further to develop practical skills and support lecture material. |