Department of Physics, Unit Catalogue 2006/07
PH30028 Real solids, surfaces & soft matter physics
| Credits: 6 |
| Semester: 1|
|Before taking this unit you must take PH20017 and take PH20019 and take PH20020|
Aims & Learning Objectives:
The aims of this unit are to introduce areas of condensed matter physics that extend beyond the conventional domain of regular, infinite, crystalline solids. After taking this unit the student should be able to:
* relate the electronic, optical and mechanical properties of real crystals to their defects;
* make quantitative estimates of the parameters that govern the behaviour of real solids;
* describe the structure and properties of amorphous solids;
* explain the basic features of the observed crystal and electronic structure of clean surfaces;
* sketch surface unit meshes and reciprocal nets and write down the associated Wood notation;
* describe, compare and contrast experimental probes of surfaces and soft condensed matter;
* describe the structure of polymers, colloids and surfactants and how these impact upon their properties.
Real Solids (8 lectures). Defects in crystals: point defects and dislocations in crystals. Effect on electronic, optical and mechanical properties. Point defects in thermal equilibrium. Self diffusion. Ionic conductivity. Colour centres. Dislocations: slip, shear strength; edge and screw dislocations. Dislocation loops and networks. Introduction to amorphous solids. Topological disorder. Determination of glass structure. Short range order, vibrational states and thermal conductivity of glasses. Surface physics (8 lectures): importance of surfaces, eg catalysis, corrosion, epitaxial growth. Clean and real surfaces. Surface energy. Surface crystal structure; relaxation and reconstruction; Wood notation. Surface electronic structure; the work function, 2-band model of surface states; adsorbates. Experimental probes of atomic and electronic structure; electron spectroscopies, low energy electron diffraction, scanning tunnelling microscopy. Soft Condensed Matter (8 lectures). Polymers: Chemical structure; Models for the conformation of polymers: the random walk, large N limit, freely jointed chains, Gaussian chains. Polymer solutions and melts. Colloids: Colloid structure, Brownian motion, sedimentation. Interacting colloid particles, phase behaviour, crystals and glasses. Surfactants: self assembly, Micelle formation, shapes of surfactant assemblies. Slow dynamics and the Glass transition. Experimental techniques: Static and dynamic light scattering; x-ray and neutron scattering.