Growth of (Cu,C)Ba$_{2}$Ca$_{2}$Cu$_3$O$_{9\pm\delta}$ thin films on flexible Hastelloy tapes

TL;DR

This paper reports the successful fabrication of a new non-toxic superconducting film, (Cu,C)Ba₂Ca₂Cu₃O₉±δ, on flexible tapes, with promising properties for high-power applications at liquid nitrogen temperatures.

Contribution

It introduces a new superconducting material, (Cu,C)Ba₂Ca₂Cu₃O₉±δ, fabricated on flexible tapes, expanding options beyond REBCO for superconducting wire applications.

Findings

Superconducting transition temperature up to 112 K.

Zero-resistance temperature around 96-98 K.

Relatively small anisotropy in resistivity under magnetic fields.

Abstract

The applications of superconducting cable or magnet require that the superconductors are made into wires or tapes. For cuprate superconductors, this is a big challenge because of the strong flux motion induced by high anisotropy, very short coherence length and strong thermal fluctuation, etc. One of the ways is to fabricate superconducting films on flexible metallic tapes with oxide buffer layers. The successful one so far is the REBa$_2$Cu$_3$O$_7$ (REBCO, RE=rare earth elements) films in tape form, as called the coated conductors. While the superconducting transition temperature of REBCO system is limited to about 90 K. Here we report the successful fabrication of another new non-toxic superconducting film, namely (Cu,C)Ba$_{2}$Ca$_{2}$Cu$_3$O$_{9\pm\delta}$ on these flexible metallic tapes with LaMnO$_3$ and CeO$_2$ as the top layers. The onset superconducting transition occurs at 112 K and 110 K, and the zero-resistance transition temperatures are about 96 K and 98 K, respectively. The temperature dependent resistivity under magnetic fields in different directions reveal a relatively small anisotropy. Further optimization of the films will improve the zero resistance transition temperature, thus can also improve the characteristic properties for applications. Our results show that the (Cu,C)Ba$_{2}$Ca$_{2}$Cu$_3$O$_{9\pm\delta}$ is a promising candidate material for the high power applications in liquid nitrogen temperature region.