NEW YORK, MARCH 3 -- A new formulation of a superconducting material loses all resistance to electricity at a record high temperature, 35 degrees better than the previously known best, scientists said today.
The finding is a significant step toward making superconductors practical, another researcher said.
Scientists at the International Business Machines Corp. Almaden Research Center said their superconducting material showed no resistance to electricity at minus 234 degrees Fahrenheit.
The material was a mix of thallium, barium, calcium, copper and oxygen, IBM announced. The same elements were used in different proportions by University of Arkansas researchers who reported zero resistance at minus 269 degrees last month.
"They've outdone us," Allen Hermann, chairman of the physics department at the University of Arkansas, said. "Well, the race is on. I'm astounded. I'm amazed."
Superconductivity is the ability to carry electricity without resistance. Scientists want to drive the temperature as high as possible to reduce or eliminate the need for chilling, in attempts to make the materials practical for use in high-speed computers, bullet trains and other applications.
IBM researchers showed their result was repeatable, and the sample expelled magnetic fields, a hallmark of superconductivity, IBM said.
Thallium is poisonous, and scientists say its potential for practical use outside the laboratory is limited. But they hope to learn enough from thallium compounds to find more suitable materials that superconduct at still higher temperatures.
Scientists want to develop materials that will superconduct at temperatures as far as possible above minus 321 degrees. That is how cold a material gets when chilled by liquid nitrogen, which is relatively cheap.
The higher the superconducting temperature is above that mark, for a material chilled by liquid nitrogen, the more current the material can carry and greater magnetic field it can withstand before losing its superconductivity.