Influence of Gd Addition on the Microstructure and Superconducting Properties of YBCO Bulk Superconductors

The influence of Gd addition on the microstructure and superconducting properties of Y-Ba-Cu-O (YBCO) bulk superconductors has been studied. Precursor powders YBa
₂
Cu
₃
O
_7-δ
(Y-123), Y
₂
O
₃
, and CeO
₂
were enriched with different amounts of GdBa
₂
Cu
₃
O
_y
(Gd-123) powder with the aim to increase critical current density J
_c
by introducing additional pinning centers. YBCO bulk superconductors with GdBa
₂
Cu
₃
O
_y
(Y123-Gd) addition were prepared by the optimized top seeded melt growth process in the form of single grains. Microstructure of prepared samples was studied by polarized light microscope. The superconducting properties were measured using a vibrating sample magnetometer in magnetic fields up to 6 T at 77 K. In spite of decreasing critical current density J
_c
in zero field at 77 K with increasing Gd concentration x almost all the samples with Gd-123 addition posses a maximum trapped magnetic field B
_tmax
higher than that for YBCO sample without any addition. In the contribution, the effect of Gd addition on Y
₂
BaCuO
₅
(Y-211) particle size, critical transition temperature T
_c
, critical current density J
_c
, and maximum trapped magnetic field B
_tmax
is reported.