Transport critical currents and flux pinning in melt-grown YBa2Cu3O7−δ

Normal-superconducting transition induced by high current densities inYBa2Cu3OGonzález1, Viña2, Currás3 et al. 2003Phys. Rev. B21060View full textAdd to dashboardCite

“…4 and 5, both J and E along the whole CVCs are approximately two orders of magnitude higher in films, and this includes J * and E * . The abundant results on transport properties for currents near the beginning of dissipation both for melttextured samples 34,35,36,37 and films 38,39,40,41 had already well established the existence of approximately a factor 10 2 between J c values of both kind of samples. From the observation of the CVCs presented in this work, it can be stated that this feature is maintained along the whole CVCs.…”

“…Despite these marked differences, the similarity of the overall quenching phenomenon seen in the CVCs for films and bulk samples demands a more exhaustive measurement of the latter, and closer comparative study between them. In fact, though there are contributions that study both type of samples at the onset of dissipation at differ-ent temperatures and magnetic fields 34,35,36,37,38,39,40,41 , we are not aware of similar studies for melt-textured samples extending to high current densities, and, in particular, the quenching effect. This paper is devoted to a systematic comparison of dissipation and particularly the quench phenomenon in both melt-textured (bulk) and thin films.…”

Effects of Texturing Mechanisms on the Critical Current Density in Sintered High-Tc Bi-2223 Superconductors

“…[11][12][13][14]. In additions, Fradina et al [15] showed that a pelletization pressure of 400-500 MPa was necessary for the quality of grain contacts in samples and the pelletization pressure should not be too large.…”

“…It is well known that size and alignment of the grains will greatly depend on the processing method employed. Currently one of the most successful processing methods is based on a peritectic growth of the superconducting phase from a partially melted mixture [11,12]. In the solid state reactions, at the end of sintering, slow cooling may be necessary to avoid internal strain in the bulk material, which could cause extensive damage at grain boundaries and micro cracking in the bulk.…”

“…The size and distribution of the interconnections and their properties greatly depend on the processing method used. Currently one of the most successful processing methods is based on a peritectic growth of the superconducting phase from a partially melted mixture [11,12]. It is believed that this processing method enhances the critical current density by growing grains, improving the grain boundary stoichiometry, the intergranular coupling and grain alignment [13,14].…”