Photoconductivity

Investigations into the electrical properties of particular metals at different temperatures led to the identification of superconductivity and the exploration of possible applications

Students learn to:

• outline the methods used by the Braggs to determine crystal structure
• identify that metals possess a crystal lattice structure
• describe conduction in metals as a free movement of electrons unimpeded by the lattice
• identify that resistance in metals is increased by the presence of impurities and scattering of electrons by lattice vibrations
• describe the occurrence in superconductors below their critical temperature of a population of electron pairs unaffected by electrical resistance
• discuss the BCS theory
• discuss the advantages of using superconductors and identify limitations to their use

Students:

• process information to identify some of the metals, metal alloys and compounds that have been identified as exhibiting the property of superconductivity and their critical temperatures
• perform an investigation to demonstrate magnetic levitation
• analyse information to explain why a magnet is able to hover above a superconducting material that has reached the temperature at which it is superconducting
• gather and process information to describe how superconductors and the effects of magnetic fields have been applied to develop a maglev train
• process information to discuss possible applications of superconductivity and the effects of those applications on computers, generators and motors and transmission of electricity through power grids