Important Facts For Prelims
Semi - Dirac Metals
- 06 Nov 2019
- 2 min read
Why in News
Researchers from the Indian Institute of Technology - Bombay have discovered special properties in a class of materials called “semi-dirac metals”.
How Semi - Dirac Metals differ from other metals?
- In general, metals are good conductors of electricity.
- A key aspect that decides the quality of conduction is the way energy depends on the momentum of electrons.
- Dirac metals differ from normal metals in that the energy depends linearly on the momentum of electrons. This difference is also responsible for their unique properties.
- Semi-Dirac metals behave like Dirac metals in one direction and like normal metals in the perpendicular directions (since their microscopic structure is different along the two directions).
- Examples of semi-dirac metals are systems such as TiO2/V2O3 nanostructures (Oxides of Titanium and Vanadium).
Properties Discovered
- The direction-dependence of microscopic properties gives Semi - Dirac material special optical properties.
- Semi-Dirac materials have very high optical conductivity of electromagnetic waves (light waves). These waves are of a specific frequency and a specific polarisation.
- Optical conductivity is a measure of the opacity offered by the material to the passage of light through it.
- Semi - Dirac materials would be transparent to light of a given frequency and polarisation when it is incident along a particular direction.
- These materials would be opaque to the same light when it falls on it from a different direction.
- There are many known applications for transparent conducting films – the common example being touch screens used in mobiles.
- The material possesses interesting thermoelectric properties.
- Thermoelectricity is a clean energy technology that uses waste heat to produce electricity typically in low power applications.
- This technology is used in efficient cars, where it is used to keep the lights on and to warm seats.
