Investigations of Material Properties at Low Temperatures

Understanding Material Properties at Low Temperatures

Material properties at low temperatures significantly differ from properties at normal or high temperatures.
Cryogenics, the study of materials at extremely low temperatures (below -150°C), investigates these variances and changes.
Important material properties studied in cryogenics include resistance to electricity, thermal capacity, ductility, and magnetism.
Materials used in cryogenic applications need to have low thermal expansion and high thermal conductivity to withstand rapid temperature changes.
Most materials will reduce in size as the temperature decreases which is because the particles are moving less and are closer together.

Thermal contraction measurements are conducted to see how much a material will shrink in extreme cold, revealing its thermal contraction coefficient.
Electrical resistance measurements at low temperatures help determine a material behaviour.
Thermal conductivity measurements reveal how well a material conducts heat in a low-temperature environment.

Superconductivity is a state of zero electrical resistance and expulsion of magnetic fields occurring in certain materials when cooled below a characteristic critical temperature.
This phenomena has significant implications for applications such as magnets for MRI scanners, electrical power cables, and magnetic levitation trains.
Superconductivity is only possible at extremely low temperatures (close to absolute zero) and understanding this trait is a significant area of cryogenics.

Materials used in constructing a cryocooler, a device that reaches low temperatures, need to have high resistance to thermal shock as the device cycles between high and low temperatures.
Rocket fuel tanks are often made of materials that contract little when cooled to prevent structural collapse when filled with cryogenic propellants.
Materials for high-speed electronic devices, such as quantum computers, need to be superconductive, highly stable, and capable of performing at extreme low temperatures.