Persistent magnetic flux and mapping of intergranular junctions in melt textured YBa/sub 2/Cu/sub 3/O/sub 7/

Abstract

Abstnct--Melt textured superconductors have been prepared with a microstructure characterized by large domains having misaligned growth fronts. An rf mutual inductance miaoprobe has been developed which allows to identify and characterise the weak link behaviour of the high angle grain boundaries separating the domains. The mechanisms of flux penetration and trapping i n a single domain sample has been analysed in the H//c configuration at low temperature ( 25 K) where Jc is essentially field independent. A consistent description of flux penetration, isothhnal remanence and magnetic hysteresis is reached in the framework of the Bean model. The small value of the lower Critical fiyld Hcl deduced from this analysis suggest that the pn-Livingston surfacebarriers are strongly reduced in melt textured ceramics as compared to single aystals.

rf impedance of sintered BSCCO and melt-textured YBCO superconductors

“…To our knowledge, but for a few reports [8]- [11], no detailed work has been reported at radio frequencies. An rf mutual inductance probe was used by Gomis et al [10] to characterize the weak link behavior of melt-textured HTS. From the analysis of the data the authors found that surface barrier effects are reduced in MT samples.…”