Cellulose-Bound Magnesium Diboride Superconductivity

TL;DR

This paper presents a new formable superconductor tape made from magnesium diboride and a polymer binder, maintaining high transition temperature but with altered transport properties, functioning as coupled Josephson junctions.

Contribution

It introduces a novel cellulose-bound magnesium diboride superconductor with preserved superconducting transition temperature and explores its transport and Josephson junction behavior.

Findings

Superconducting transition temperature remains at 38K.

Transport critical current density decreases by seven orders of magnitude.

Material behaves as a system of coupled Josephson junctions.

Abstract

Two-phase superconductor tapes were produced by blending high purity magnesium diboride powder with a liquid ethylcellulose-based polymeric binder. This procedure produced a material which is easily formable with a high superconducting transition temperature (38K). We show that the bulk superconducting properties are not affected by the presence of the binder, nor is there any evidence of a chemical reaction between the superconducting particles and the binder. However, the transport properties of the material are strongly affected by the presence of the binder, which leads to a seven order of magnitude increase of the normal state resistance along with a seven order of magnitude decrease of the transport critical current density. This new material is shown to be equivalent to a system of coupled Josephson junctions.