Influence of Precursor Composition on the Microstructure and Superconducting Properties of Dy-Ba-Cu-O filaments

Dy-Ba-Cu-O filaments have been successfully fabricated by a solution spinning method. The relationship between the partial melting temperature and the transport Jc value at 77 K of the filamentary sample was systematically investigated. Two kinds of precursor filaments with starting composition of Dy:Ba:Cu = 1.18:2.12:3.09 (sample A)and Dy:Ba:Cu = 1.00:2.00:3.00 (sample B) were partially melted in 1%O2 + Ar atmospheric gas and oxygenated in pure 100% O2 gas. Samples partially melted at a wide temperature range of 990-1040 deg. C had Jc values higher than 104 A/cm2. Both sample A and sample B partially melted at 1020 deg. C exhibited the maximum Jc value higher than 4.2 x 104 A/cm2 and 2.0 x 104 A/cm2, respectively. These samples had a dense microstructure consisting predominantly of Dy123 and finely dispersed Dy211 particles. The Dy211 particles with a diameter of about 1μm were finely dispersed in sample A, while the particles with a diameter of about 5μm were observed in sample B. The Jc values of both samples were maintained about 2.0 x 103 A/cm2 up to 14 T