Effect of SiC-Impurity Layer and Growth Temperature on MgB2 Superconducting Tapes Fabricated by HPCVD

TL;DR

This study investigates how SiC-impurity layers and growth temperature affect the microstructure and superconducting properties of MgB2 tapes fabricated by HPCVD, revealing optimal conditions for enhanced critical current density.

Contribution

It introduces a method of incorporating SiC-impurity layers and analyzes their effect on MgB2 tapes grown over a temperature range, highlighting improved flux pinning and superconducting performance.

Findings

MgB2/SiC/Cu tape at 540°C has Tc of ~37.7 K

MgB2/SiC/Cu tapes show improved flux pinning with increasing temperature

Critical current density behavior varies with SiC layer and temperature

Abstract

The influence of SiC-impurity layer and growth temperature on microstructure and superconducting properties were studied for MgB2 superconducting tapes. The pulsed laser deposition (PLD) system was used for the deposition of amorphous SiC-impurity layers on the flexible metallic Cu (001) tapes. The MgB2 superconducting tapes were fabricated by growing MgB2 films on the top of SiC/Cu tapes over a wide temperature range of 460 - 600 {\deg}C by using hybrid physical-chemical vapor deposition (HPCVD) system. Among all tapes, the MgB2/SiC/Cu tape deposited at a temperature of 540 {\deg}C has the highest Tc of ~ 37.7 K. Scanning electron microscopy (SEM) images revealed the hexagonal shaped MgB2 grains with good connectivity, and their sizes were found to vary with growth temperatures. As compared to MgB2/Cu tapes, the MgB2/SiC/Cu tapes exhibited opposite trend in the dependence of critical current density (Jc) with deposition temperatures. The improved Jc (H) behavior could be explained on the basis of the enhanced flux pinning force density (Fp) for MgB2/SiC/Cu tapes upon increasing growth temperature.