Progress

01Symmetry0 of 5

• Models: simple pictures that still predict things
• Why atoms hold together and how particles attract
• Symmetry operations and rotation axes
• Mirror planes, inversion and improper rotation
• Point groups: sorting molecules by their symmetry

02Crystals and diffraction0 of 8

• Unit cells, crystal systems and Bravais lattices
• Crystal symmetry: glides, screws and space groups
• Reading a space group symbol
• Close packing and the holes between the atoms
• Ionic structures: rock salt, zinc blende, antifluorite, CsCl and rutile
• Measuring crystal structure: Miller indices and Bragg diffraction
• Ionic or covalent, ionic radii and radius ratios
• Lattice enthalpy: the Born–Mayer equation and its trends

03Solid-state materials0 of 10

• Energy bands: how a pile of atoms becomes a metal, semiconductor or insulator
• Conductors in one, two and three dimensions
• Superconductivity, BCS theory and Mott-Hubbard localisation
• Bonding sets the bands: NaCl, SiC, TiS2 and ReO3
• Conductivity, carriers and how temperature changes them
• Doped semiconductors, p-n junctions and solar cells
• Dielectrics, capacitors and the structure of barium titanate
• Polarisation loops, lone pairs, piezoelectrics and second harmonic generation
• Magnetic moments, diamagnetism and paramagnetism
• Magnetic order: ferro-, antiferro- and ferrimagnets and the exchange that makes them

04Statistical mechanics0 of 3

• Microstates, configurations and the Boltzmann distribution
• Temperature, absolute zero and the zeroth law
• The partition function, degeneracy and characteristic temperature

05Thermodynamics0 of 6

• The first law: internal energy, work and heat
• The second law and entropy
• Heat flow, the third law and residual entropy
• Open systems, free energy and spontaneity
• The ideal gas from statistical mechanics
• Vibrations and the Einstein solid

06Defects and phase transitions0 of 7

• Defects: why every real crystal has some, and how many
• Ionic conductivity: ions hop through gaps, and doping adds more gaps
• Phase transitions need interactions, and only sharpen with many particles
• Simulations: Monte Carlo, molecular dynamics and the Ising magnet
• Mean-field theory: replace the crowd with its average and a transition appears
• The van der Waals gas: two corrections to the ideal gas that predict liquids
• Chemical potential decides which phase wins, and phase diagrams map the winners

07Heat capacity, kinetics and glasses0 of 3

• Heat capacity and calorimetry: how much heat it takes, and how transitions show up
• Nucleation and growth: a new phase must first beat a surface-energy barrier
• Glasses: a liquid that was cooled too fast to crystallise

08Soft matter and liquids0 of 6

• Soft matter and the kT yardstick
• Self-organisation and mesophases between liquid and crystal
• The order parameter and the hard-particle model of nematics
• Excluded volume, entropy and Onsager theory of the nematic
• Nematics in use: polarised light, electric fields and displays
• Random walks and diffusion: Fick's two laws

09Chemical kinetics0 of 3

• Rate laws, half-lives and diffusion-controlled reactions
• Activation barriers, transition state theory and catalysis
• Elementary steps, mechanisms and detailed balance

10Surfaces and interfaces0 of 6

• Surfaces cost energy: surface tension, work of cohesion and why drops are round
• Wetting: spreading, contact angle, Young's equation and measuring surface tension
• Friction and adhesion: why surfaces grip and how glues hold
• Adsorption onto solids: physisorption, chemisorption, thin films and self-assembled monolayers
• Langmuir and BET isotherms: how much gas a surface holds, and how big the surface is
• The Gibbs adsorption isotherm: surface excess, surfactants and the cmc

11Metal-organic frameworks0 of 5

• Building MOFs: nodes, linkers and crystal engineering
• Thermal expansion and why cyanide frameworks can shrink when heated
• Tuning NTE: how the metal ion and crystal field stabilisation set bond strength
• MOFs as sponges for gas: hydrogen, carbon dioxide and methane
• MOFs that act as magnets, wires, proton conductors and spin switches

12Practice exam questions0 of 4

• Practice exam questions SA1 to SA5, with answers built from the lectures
• Practice paper 1: Lectures 1 to 11, ten questions with model answers
• Practice paper 2: statistical mechanics to glasses (Lectures 12 to 25)
• Practice paper 3: soft matter, kinetics, surfaces and MOFs (Lectures 26 to 39)