Latest Superconductivity Record At Antarctic Temps Stirs Up Physicists
Superconductors, materials that conduct electricity with no resistance, achieved a new record high for temperature, an advance that could pave the way for the development of room-temperature superconductors.
Superconductivity currently works only at very cold temperatures. The new record-breaking temperature achieved by a team of researchers is even considered very cold. It is comparable to the chilly conditions in Antarctica, which means that the temperature is naturally found on the surface of the Earth.
Scientists have long attempted to develop superconductors that work at room temperature and do not require burdensome and energy-hogging supercooling.
Prior to the new record, the highest temperatures that have been achieved for superconductors to work, called their critical temperatures, were minus 220 degrees Fahrenheit at normal pressures and minus 164 F at high pressures.
Mikhail Eremets, from the Max Planck Institute for Chemistry in Germany, and colleagues achieved superconductivity at a critical temperature of minus 94 F, which is about 34 F warmer when compared with the coldest temperatures in Antarctica.
Using a diamond anvil, Eremets and colleagues squeezed small amounts of hydrogen sulfide to nearly 1.6 million times atmospheric pressure.
Hydrogen sulfide, a toxic and colorless gas responsible for the distinct smell of rotten eggs, is transformed into a metal when it is chilled at high pressure.
The researchers discovered that under pressure from the diamond anvil, hydrogen sulfide is transformed into a superconducting material at temperatures that break prior records.
The record-high temperature that the researchers achieved, however, required extreme pressures of about 200 gigapascals.
Eremets explains that 10 gigapascals is the pressure that is used in the industry to produce synthetic diamonds. The pressure in the core of the Earth, on the other hand, is 360 gigapascals.
"On cooling, we see signatures of superconductivity: a sharp drop of the resistivity to zero and a decrease of the transition temperature with magnetic field, with magnetic susceptibility measurements confirming aTc of 203 kelvin," the researchers reported in their study, which was published in the journal Nature on Aug. 17.
The researchers acknowledged that extremely high pressures would likely make superconductors that work at room temperature impractical, but they hope that they can find other hydrogen-based materials that can superconduct at relatively high temperature and normal pressures.
The researchers said that findings on superconductors that work at room temperatures would mean a revolution in electronics as they could sustain current indefinitely without the need to top up power.
Photo: Trevor Prentice | Flickr