Direct Observation of Long-Term Durability of Superconductivity in YBa$_2$Cu$_3$O$_7$-Ag$_2$O Composites

TL;DR

This study demonstrates that YBa₂Cu₃O₇-Ag₂O composites maintain their superconductivity over 14 years, showing environmental stability and a critical temperature of 91 K, unlike pure silver additions.

Contribution

It provides the first long-term observational evidence of the durability of superconductivity in YBa₂Cu₃O₇-Ag₂O composites over nearly 14 years.

Findings

Superconductivity persists with a T_c of 91 K after 14 years.

Long-term stability is achieved only with Ag₂O addition, not pure Ag.

Environmental stability of high-temperature superconductivity demonstrated.

Abstract

We report direct observation of long-term durability of superconductivity of several YBa$_2$Cu$_3$O$_7$-Ag$_2$O composites that were first prepared and studied almost 14 years ago [J. J. Lin {\it et al}., Jpn. J. Appl. Phys. {\bf 29}, 497 (1990)]. Remeasurements performed recently on both resistances and magnetizations indicate a sharp critical transition temperature at 91 K. We also find that such long-term environmental stability of high-temperature superconductivity can only be achieved in YBa$_2$Cu$_3$O$_7$ with Ag$_2$O addition, but not with pure Ag addition.