Flux pinning by crystalline precipitates in an amorphous superconducting matrix

Abstract
The introduction of a small volume fraction of σ‐phase MoRu particles into an otherwise amorphous superconducting matrix of composition (Mo0.6Ru0.4)80Si10B10 is observed to result in substantial flux‐pinning interactions and an increase of the sample Tc. The critical current density in the presence of an externally applied field is increased by two to three orders of magnitude as compared to that of the amorphous matrix alone. The proximity effect explains the observed increase of Tc which results from the σ‐phase precipitate particles having a Tc higher than that of the amorphous matrix.