Superconductivity
Context: IISc researchers have reported superconductivity at room temperature. Their finding, now under review, will be a breakthrough if verified.
Background:
- Superconductivity is a phenomenon that, so far, has been possible only at extremely low temperatures, in the range of 100°C below zero.
- The search for a material that exhibits superconductivity at room temperature, or at least manageable low temperatures, has been going on for decades, without success.
- If the claimed discovery were confirmed, it could be one of the biggest breakthroughs in physics in this century so far.
What is superconductivity?
- It is a state in which a material shows absolutely zero electrical resistance. While resistance is a property that restricts the flow of electricity, superconductivity allows unhindered flow.
- In a superconducting state, the material offers no resistance at all. All the electrons align themselves in a particular direction, and move without any obstruction in a “coherent” manner.
- Because of zero resistance, superconducting materials can save huge amounts of energy, and be used to make highly efficient electrical appliances.
Two fundamental properties of a superconductor:
- Zero resistance to electrical current.
- Diamagnetism
Also Read : NPT and NSG
Diamagnetism is a property opposite to normal magnetism that we are used to. A diamagnetic substance repels an external magnetic field, in sharp contrast to normal magnetism, or ferromagnetism, under which a substance is attracted by an external magnetic field.
How rare is this?
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- The problem is that superconductivity, ever since it was first discovered in 1911, has only been observed at very low temperatures, somewhere close to what is called absolute zero (0°K or -273.15°C).
- In recent years, scientists have been able to find superconductive materials at temperatures that are higher than absolute zero but, in most cases, these temperatures are still below -100°C and the pressures required are extreme. Creating such extreme conditions of temperature and pressure is a difficult task.
- Therefore, the applications of superconducting materials have remained limited as of now.
