From RE-211 to RE-123. How to control the final microstructure of superconducting single-domains

TL;DR

This review discusses techniques for producing YBCO single-domains, focusing on microstructure control, the role of RE-211 particles, defect formation, and methods like Infiltration and Growth to optimize properties.

Contribution

It provides a comprehensive overview of microstructure control methods and the influence of RE-211 particles in YBCO single-domains, highlighting recent advances and challenges.

Findings

RE-211 particles influence microstructure and properties.

Infiltration and Growth is effective for microstructure control.

RE-211 coarsening can be limited by specific techniques.

Abstract

This paper reviews the usual techniques for producing YBCO-type single-domains and the microstructure of the as-obtained samples. The problems of seed dissolution and parasite nucleations are discussed in details. Formation of microstructural defects, such as pores and cracks, are examined. An important part of this review is devoted to the study of the influence of RE-211 particles [RE2BaCuO5 where RE denotes Y, Yb, Nd, Sm, Dy, Gd, Eu or a mixture of them. Generally Nd4Ba2Cu2O10 is preferred to Nd2BaCuO5] on the microstructure and properties of RE-Ba-Cu-O single-domains. Trapping/Pushing theory is described in order to explain the spatial distribution of RE-211 particles in the RE-123 [(RE)Ba2Cu3O7-d] monoliths. Formation of RE-211-free regions is discussed. Different ways to limit the RE-211 coarsening are reviewed. Microstructural defects in the RE-123 matrix caused by the RE-211 particles are presented. It is also shown that RE-211 particles play a significant role on the mechanical properties of single-domain samples. We finish this review by discussing the Infiltration and Growth process as a good technique to control the microstructure.