Larger grains in high-Tc superconductors synthesized by the solid-state reaction route

TL;DR

This study demonstrates that combining solid-state synthesis with top-seeded melt growth can produce high-Tc superconductors with significantly larger grains, leading to improved magnetic properties.

Contribution

It introduces a method to synthesize high-Tc superconductors with larger grains using combined solid-state and melt growth techniques, enhancing magnetic performance.

Findings

Grain size increased up to 0.1 mm in synthesized samples.

Magnetization width ΔM significantly increased.

Pinning mechanism remains similar to standard polycrystalline superconductors.

Abstract

Solid-state synthesis is widely used in exploratory research to study various structural modifications that affect the properties (critical temperature, critical current density, irreversibility field, etc.) of superconductors. The popularity of this method is due to its relative simplicity and availability of the necessary equipment. Combining solid-state synthesis and top-seeded melt growth allows us to increase the grain size in a Tm- and Nd-based 1-2-3 superconductor. Samples with a grain size up to 0.1 mm have been obtained. X-ray diffraction, scanning electron microscopy and magnetization measurements have been used for investigating this superconducting material. The magnetization width {\Delta}M has increased significantly in the synthesized samples. However the temperature dependence of the intragrain critical current density and the pinning force scaling give evidences that the pinning mechanism in the obtained superconductor is essentially the same as in polycrystalline superconductors synthesized by standard solid-state technology. The increase in grain size in the synthesized samples is the main reason for the high values of {\Delta}M.