Superconducting Nanocomposites: Enhancement of Bulk Pinning and Improvement of Intergrain Coupling

TL;DR

This paper introduces a sonochemical synthesis method for superconducting nanocomposites that enhances magnetic pinning and intergrain coupling, leading to improved superconducting properties.

Contribution

It presents a novel synthesis technique for embedding magnetic and nonmagnetic nanoparticles into superconductors, improving their magnetic and structural performance.

Findings

Fe2O3 nanoparticles significantly increase magnetic irreversibility.

Mo2O5 nanoparticles also enhance pinning but to a lesser extent.

Theoretical model for magnetic pinning by ferromagnetic nanoparticles is developed.

Abstract

Heterogeneous sonochemical method was applied for synthesis of novel superconducting nanocomposites consisting of magnetic (and/or nonmagnetic) nanoparticles embedded into the bulk of ceramic superconductors. In addition to in-situ production of the efficient pinning centers, this synthesis method considerably improves the interbrain coupling. Significant enhancement of the magnetic irreversibility is reported for Fe2O3 nanoparticles embedded into the bulk of MgB2 superconductor. Nonmagnetic Mo2O5 nanoparticles also increase pinning strength, but less than magnetic Fe2O3. Detailed magnetization and electron microscopy characterization is presented. Theory of bulk magnetic pinning due to ferromagnetic nanoparticles of finite size embedded into the superconducting matrix is developed.