Superconducting phosphorus

Science. 1968 May 31;160(3831):994-5. doi: 10.1126/science.160.3831.994.

Abstract

Phosphorus, the element itself, becomes superconducting near 4.7 degrees K and at pressures exceeding 100 kilobars. This constitutes one of the four last missing links in the proof that superconductivity is normal behavior for every truly metallic sp element. The three remaining ones are arsenic, sulfur, and iodine.