Lecturers: Marin Alexe, Tom Hase and Peng Wang

Weighting: 15 CATS

Characterising and, where possible, controlling the structure of materials is one the most important areas of research in science. The microscopic structure of a material determines its mechanical strength, its electrical properties and, at surfaces, the way the material interacts with the outside world (for example as a catalyst, in electrical contacts or as it corrodes). The module is split into three parts. Part 1 looks at the how and why structures form and the use of x-ray methods for identifying and studying their structure. The second half switches probe, and focuses on the use of electrons to study materials exploring both electron diffraction and imaging. The third part explore how the distribution of charge and current flows affect the structural and electrical properties of insulators and semiconductors in devices. The course aims to link structure with underlying functional properties, taking topical examples from the recent literature.

Aims:
To cover a range of theoretical concepts and practical techniques used in experimental condensed matter physics. Topics covered will be in the areas of the structural and electrical properties of solids.

Objectives:

By the end of the module, students should be able to:

• Describe experimental techniques to measure physical properties of materials
• Characterise crystal structures and explain how they are determined experimentally
• Explain the operation of an electron microscope and how to interpret the data obtained
• Describe the physics of some semiconductor devices
• Explain piezo- pyro- and ferroelectricity and its uses
• Start postgraduate research in materials physics

Syllabus:

1. Part I: Structure of solids – revision of second and third year material on bonding, crystal structure and symmetry; Crystal growth; Phase Transitions and Phase Diagrams; Kinematical X-ray diffraction: revision, theory and analysis; Real crystals and their defects; Surfaces, thin films and growth techniques;
2. Part 2: Electron diffraction and imaging for materials characterisation -Introduction to Transmission Electron Microscopy (TEM): Resolution with electrons, Electron scattering, Instruments to achieve atomic resolution; Electron diffraction from crystals: Indexing diffraction patterns; Bright field and dark field imaging, Atomic resolution contrast mechanisms, STEM Z‑contrast imaging, Defects and interface characterisation, 3D imaging; Practical aspects of the techniques
3. Part 3 Semiconductors Devices; Revision of second and third year material on semiconductors and the photoelectric effect; electronic transport in semiconductor devices; metal-semiconductor contacts; Metal-oxide-semiconductor transistors; Devices based on quantum tunnelling; Non-volatile memories; Piezoelectric and pyroelectric materials and applications; Ferroelectric materials and multiferroics;

Commitment: 30 Lectures

Assessment: 2 hour examination

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