Relevance:
A group of researchers from Italy used “state-of-the-art theoretical and computational approaches” to explain the superconductivity in Mercury using BCS theory.
About Superconductivity:
- Superconductivity is the property of certain materials to conduct direct current (DC) electricity without energy loss when they are cooled below a critical temperature (Tc).
- These materials also expel magnetic fields as they transition to the superconducting state.
- It is a quantum phenomenon.
- Discovered more than 100 years ago in mercury cooled to the temperature of liquid helium (4 kelvins – 4 degrees above absolute zero)).
- The phenomenon was also observed in other materials at very low temperatures.
- The materials included several metals and an alloy of niobium and titanium that could easily be made into wire.
High-temperature superconductors
- High-temperature superconductors (high-Tc or HTS) are defined as materials that behave as superconductors at temperatures above 77 K (−196.2 °C), the boiling point of liquid nitrogen.
- First HTS was discovered in 1986.
- Advantages
- They can be cooled by using liquid nitrogen, as opposed to the previously known superconductors which require expensive and hard-to-handle coolants, primarily liquid helium.
- Their superconductivity in higher magnetic fields than previous materials.
- The majority of high-temperature superconductors are ceramic materials, as opposed to the previously known metallic materials.
Superconductivity Facts:
- Superconductivity was discovered in 1911 by Heike Kamerlingh-Onnes – 1913 Nobel Prize in Physics.
- 5 Nobel Prizes in Physics have been awarded for research in superconductivity.
- Approximately half of the elements in the periodic table display low temperature superconductivity, but applications of superconductivity often employ easier to use or less expensive alloys. For example, MRI machines use an alloy of niobium and titanium.
BCS Theory:
- The BCS theory or Bardeen-Cooper-Schrieffer theory.
- Theory of superconductivity developed by John Bardeen, Leon N Cooper and John R. Schrieffer in 1957.
- The Nobel Prize in Physics 1972 was awarded jointly to the 3 scientists.
- Related term – Cooper pairs.
- In BCS superconductors, vibrational energy released by the grid of atoms encourages electrons to pair up, forming so-called Cooper pairs. These Copper pairs can move like water in a stream, facing no resistance to their flow, below a threshold temperature.
Reference: The Hindu
