Context: A team of physicists in New York has discovered a material that conducts electricity with perfect efficiency at room temperature — a long-sought scientific milestone. 

• The hydrogen, carbon and sulfur compound operates as a superconductor at up to 59 degrees Fahrenheit, the team reported today in Nature. That’s more than 50 degrees hotter than the previous high-temperature superconductivity record set last year.

About the new material

• A new material composed of carbon, hydrogen and sulphur superconducts at 15 degrees Celsius.
• However, it needs ultrahigh pressure of about 2 million atmospheres to achieve this transition, putting off any thoughts of application to the future.
• The pressure they needed was 267 Gigapascals (GPa), or 2.6 million atmospheres.
• The pressure at the centre of the Earth is 360 GPa, so it is 75% of the pressure at the centre of the Earth.

Key findings

• A mixture of carbon, hydrogen and sulfur was put in a microscopic niche carved between the tips of two diamonds (diamond anvil) and laser light was used on them to trigger chemical reactions.
• To verify that this phase was indeed a superconductor, the group ascertained that the magnetic susceptibility of the superconductor was that of a diamagnet.
• A superconducting material kept in a magnetic field expels the magnetic flux out its body when cooled below the critical temperature and exhibits perfect diamagnetism.
• It is also called the Meissner effect which simply means that magnetic lines do not pass through superconductors in a magnetic field.
• If researchers can stabilise the material at ambient pressure, applications of superconductivity at room temperatures could be achieved and will be within reach.
• Superconductors that work at room temperature could have a big technological impact, for example in electronics that run faster without overheating.

Note: Meissner Effect: When a material makes the transition from the normal to the superconducting state, it actively excludes magnetic fields from its interior.
About Superconductivity

• A superconductor is a material, such as a pure metal like aluminium or lead, that when cooled to ultra-low temperatures allows electricity to move through it with absolutely zero resistance.
• Kamerlingh Onnes was the first scientist who figured out exactly how superconductor works in 1911.
• Simply put, superconductivity occurs when two electrons bind together at low temperatures.
• They form the building block of superconductors, the Cooper pair.
• This holds true even for a potential superconductor like lead when it is above a certain temperature.

About Superconductors

• Superconductors are materials that address this problem by allowing energy to flow efficiently through them without generating unwanted heat.
• They have great potential and many cost-effective applications.
• They operate magnetically levitated trains, generate magnetic fields for MRI machines and recently have been used to build quantum computers, though a fully operating one does not yet exist.

Issues with superconductors

• They have an essential problem when it comes to other practical applications: They operate at ultra-low temperatures.
• There are no room-temperature superconductors. That “room-temperature” part is what scientists have been working on for more than a century.
• The amount of energy needed to cool a material down to its superconducting state is too expensive for daily applications.