Multi-seeded melt growth (MSMG) of bulk Y-Ba-Cu-O using thin-film seeds

TL;DR

This paper introduces a novel multi-seeded melt growth method for bulk YBCO using thin-film seeds, improving control over grain boundaries and reducing contamination, leading to higher quality superconducting materials.

Contribution

It demonstrates the first use of thin-film YBCO and SmBCO seeds in MSMG, enabling precise orientation control and cleaner grain boundary formation in bulk YBCO.

Findings

Thin-film seeds reduce contamination in bulk YBCO.

Grain boundary quality improves with increased seed contact angle.

Continuous growth at (110)/(110) boundaries avoids liquid trapping.

Abstract

Y-Ba-Cu-O (YBCO) and Sm-Ba-Cu-O (SmBCO) thin films have been used for the first time as heterogeneous seeds to multi-seed successfully the melt growth of bulk YBCO in a multi-seeded melt growth (MSMG) process. The use of thin film seeds, which may be prepared with highly controlled orientation (i.e. with a well-defined a-b plane and precisely known a-direction), is based on their superheating properties and reduces significantly contamination of the bulk sample by the seed material. A variety of grain boundaries were obtained by varying the angle between the seeds. Microstructural studies indicate that the extent of residual melt deposited at the grain boundary decreases with increasing grain boundary contact angle. It is established that the growth front proceeds continuously at the (110)/(110) grain boundary without trapping liquid, which leads to the formation of a clean grain boundary.