简体中文
A controversial study related to superconductors has drawn global attention.
In the study, a group of South Korean researchers claimed they had created a room-temperature, ambient-pressure superconducting material – LK-99.
However, a team of researchers from the Institute of Physics under the Chinese Academy of Sciences determined that LK-99 cannot show superconductivity at room temperature, and said a Cu2S impurity contained in LK-99 is the "most likely" reason leading to the false claim.
Many research teams around the world have conducted confirmatory experiments and theoretical computational analyses of LK-99, and although the results are not entirely consistent, none have confirmed that the material has superconductivity capacity at room temperature, Luo Jianlin, a researcher on the Institute of Physics team, told CGTN via email.
The study by Luo's team pointed out that the LK-99 sample reportedly contained a certain amount of Cu2S impurity, which may have caused the so-called superconducting behavior.
The Chinese researchers said in their own study that Cu2S undergoes a structural phase transition from a hexagonal structure at high temperatures to a monoclinic structure at low temperatures at around 100 degrees Celsius.
"When the phase transition occurs, the resistivity drops by 3-4 orders of magnitude, making the LK-99 sample look like superconductivity, but it's actually not," Luo said.
Why are superconductors significant?
Superconductors are materials that have zero electric resistance and can expel magnetic fields, through which electricity can pass without losing energy.
However, temperature and pressure greatly restrict the application of known superconducting materials, Luo explained, adding that that the exploration of room-temperature, ambient-pressure superconductors is the core of superconducting materials research, and is a dream of researchers in the field.
He told CGTN that realizing superconductivity at room temperature and ambient-pressure is of great significance because it could greatly change people's daily lives.
"Such materials would make MRI exams more convenient and have higher resolution, and superconducting maglev trains would make travel faster and safer," Luo said, adding that superconducting quantum computing might be possible at room temperature, and it could lead to lossless power transmission and solve the problem of energy shortage.
The researcher said that while the exploration of room-temperature superconductors at ambient-pressure has not yet made much progress around the world, there has been significant developments under high pressure.
"The superconducting transition temperature of some hydrogen-rich materials, such as LaH10, is close to room temperature," Luo said. "At present, scientists around the world are working hard to make breakthroughs in the exploration of superconductors at ambient-pressure."
(CGTN)
