Department of Physics, Unit Catalogue 2011/12 

Credits:  6 
Level:  Intermediate (FHEQ level 5) 
Period: 
Semester 2 
Assessment:  EX 100% 
Supplementary Assessment:  PH20017  Mandatory Extra Work (where allowed by programme regulations) 
Requisites:  Before taking this unit you must (take PH10005 or take PH10053) and take PH10007 and take PH10008 and take PH20029 
Description:  Aims: The aims of this unit are to introduce students to the basic concepts and models of solid state physics, with an emphasis on crystalline, electronic and magnetic structure. Learning Outcomes: After taking this unit the student should be able to: * know the ways in which crystal structures are described formally and relate structures in real space to those in reciprocal space; * describe how Xray and neutron diffraction is related to the properties of the reciprocal lattice, and used in structural studies. * discuss why classical theories of electrons in solids fail, and why they have to be treated quantum mechanically; * 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; * describe classical theories of diamagnetism, paramagnetism, and the ferromagnetic properties of materials; * describe how crystalline structures vibrate, and the associated theories of heat capacity. Skills: Numeracy T/F A, Problem Solving T/F A. Content: Crystal structures (4 hours): Translational symmetry; lattices and basis, Miller indices. Diffraction of waves in crystalline structures; Bragg law, the reciprocal lattice and Brillouin zones. Xray and neutron diffraction studies of crystal structures. Free electron theory of solids (4 hours): The classical free electron theory and its failures. 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 (5 hours): The effect of crystalline periodicity. Energy band diagrams and effective masses. The distinction between metals, semiconductors and insulators. Electrons and holes. Basic properties of semiconductors; the effects of doping, donors and acceptors. Magnetism (3 hours): Permeability and magnetic susceptibility. The origin of magnetic moments in solids. Classical models of diamagnetism and paramagnetism. Ferromagnetism and the exchange interaction. Ferromagnetic MH loops. Paul paramagnetism; and itinerant electron ferromagnetism in metals. Lattice dynamics (4 hours): Optical and acoustic vibrations. Phonons. Classical and quantum theories of heat capacity. 
Programme availability: 
PH20017 is Compulsory on the following programmes:Department of Physics
PH20017 is Optional on the following programmes:Department of Physics
