Change of Superconducting Properties of Single-Grain Sm–Ba–Cu–O Bulk by Sm/Ba Substitution Effect

Several studies showed that the SmBa
₂
Cu
₃
O
_7-δ
(Sm123, SmBCO) achieve higher critical current density (J
_c
) and critical transition temperature (T
_c
) in comparison to the YBa
₂
Cu
₃
O
_7-δ
. On the other hand, the high sensitivity of Sm/Ba substitution on the temperature of solidification is caused by changes of Sm solubility in the Sm123, which can be an obstacle to the fabrication of SmBCO single grains with homogenous superconducting properties. We prepared Sm123 single-grain bulk superconductors with the addition of 1 wt % CeO
₂
and BaO
₂
, fabricated via the top-seeded melt growth process in air applying the slow cooling time-temperature profile. The evaluation of a substitution effect was based on an analysis of local superconducting properties and also on the results of the energy-dispersive X-ray spectroscopy (EDS) analysis from different sample location.