Superconducting metals and X-ray crystallography

Superconducting Metals

Superconductivity refers to the complete disappearance of electrical resistance in certain materials when they are cooled below a specific temperature called the ‘critical temperature’.
Superconductors can carry an electric current indefinitely without any energy loss, which makes them extremely efficient for certain applications.
There are two types of superconductors: Type I which completely lose resistance at their critical temperature, and Type II which transition more gradually and can carry higher current densities.
Some examples of superconducting metals include mercury, lead, and aluminium. Mercury was the first known superconductor and displays this property below -269 degrees Celsius.
Superconductivity comes with the persuasive queerness of a Meissner effect, which says a superconductor in its superconducting state will repel a magnetic field. A magnet moving by a conductor induces currents in the conductor. But, the superconductor has no resistance, meaning the induced currents won’t decay.

High-temperature superconductors are materials that display superconducting properties at temperatures above -196 degrees Celsius, which is the boiling point of nitrogen.
Discovered in 1986, these materials are very valuable since cooling to these temperatures can be achieved more feasibly than the extreme low temperatures needed for classic superconductors.
The first high-temperature superconductor discovered was LaBaCuO (lanthanum-barium-copper oxide) which works as a superconductor up to -183 degrees Celsius.
Many high-temperature superconductors are ceramics, usually containing planes of copper and oxygen atoms.

Superconductors are used in MRI scanners in hospitals as they can create very high magnetic fields with little energy input.
They are also used in electric power grids for efficient transmission of electricity, and in magnetically levitated trains which reduce friction and increase speed.
In the future, they could enable quantum computing technology, as superconducting circuits can act as qubits, the basic units of information in a quantum computer.

X-ray crystallography is a technique used to determine the atomic and molecular structure of a crystal.
The technique involves shining X-rays onto a crystal and measuring the way they get diffracted by the crystal’s structure. The diffraction pattern is then used to solve the structure of the crystal.
X-ray crystallography can reveal the size of atoms, the lengths and types of chemical bonds, and the atomic-scale differences among various materials, especially minerals and alloys.
It has been instrumental in the discovery of the helical structures of DNA, the double helix, by Rosalind Franklin and Maurice Wilkins.
It also has wide variety of uses in different fields such as chemistry, physics, materials science, and biology to study protein structures, crystalline phase transformations, stress-strain behaviour etc.