Functional Properties: Thermal, Electrical and Magnetic Behaviour
A unified introduction to heat transport, charge transport, dielectric response and magnetism in engineering materials.
Properties emerge from carriers
Thermal, electrical and magnetic behaviour depend on the movement or alignment of electrons, phonons, ions and magnetic moments. Structure and defects scatter or constrain these carriers.
Thermal transport
Metals conduct heat mainly through electrons, while ceramics and polymers rely more on lattice vibrations. Porosity, interfaces and temperature can strongly reduce conductivity.
Electrical response
Conductors, semiconductors and insulators differ in available electronic states and carrier density. Doping, temperature and defects tune conductivity over many orders of magnitude.
Magnetic behaviour
Diamagnetic, paramagnetic, ferromagnetic and antiferromagnetic responses arise from atomic moments and their interactions. Grain size, texture, stress and heat treatment influence practical magnetic properties.
Working rule
Define frequency, field, direction and temperature when specifying functional properties. The measurement condition is part of the property.