The case of the vanishing superconductivity Available to Purchase

A ternary superconductor, $ErRh4B4,$ does an astonishing thing as its temperature is reduced: Although at 8.6 K it becomes superconducting, as the temperature is reduced further, to 0.9 K, the superconductivity disappears. This discovery was scheduled to be reported by Bernd T. Matthias (University of California, La Jolla and Bell Labs) in a postdeadline paper at the March meeting of The American Physical Society in San Diego. Matthias says that this is the first time an ordered crystal has lost its superconductivity as the temperature is lowered.