High transition temperature superconductor LaBa2Cu3O7−<i>y</i> with zero resistance at 92 K

Abstract

Samples of LaBa2 Cu3 O7−y have been synthesized, which show a superconducting transition above 90 K. One of the samples shows a superconducting transition with an onset at 93 K and a zero resistivity at 92 K. These temperatures are the highest among those reported so far on this system and even higher than those in YBa2 Cu3 O7−y. The magnetic susceptibility measurement also shows that it has a superconducting transition with onset at around 93 K. To synthesize such good LaBa2 Cu3 O7−y requires two important procedures. First is sintering above 950 °C in N2 gas atmosphere and the second is annealing at 300 °C in dried O2 gas atmosphere.