Investigation of inter- and intragrain critical currents in high Tc ceramic superconductors

Autor:	Th. Wolf, B. Runtsch, I. Apfelstedt, R. Meier-Hirmer, U. Wiech, C. Keller, H. Küpfer, R. Flükiger, A. Turowski
Rok vydání:	1988
Předmět:	Superconductivity Flux pinning High-temperature superconductivity Materials science Condensed matter physics General Physics and Astronomy Magnetic susceptibility law.invention law Electrical resistivity and conductivity Percolation General Materials Science Grain boundary Current density
Zdroj:	Cryogenics. 28:650-660
ISSN:	0011-2275
DOI:	10.1016/0011-2275(88)90148-8
Popis:	Polycrystalline sintered bulk samples of REBa 2 Cu 3 O 7 with RE = Y , Gd were studied by a.c. susceptibility and an inductive measurement technique which allows the separation of intergrain (transport) from intragrain critical current density. Field and temperature dependence of the intergrain current are compared with theoretical predictions for a weakly coupled grain structure. Up to fields 0.3 T the weak link character of the intergrain current predominates. At higher fields it changes and points to a percolation current via superconducting grain boundaries. A quantitative correlation between intragrain current and twin spacing is hidden, probably by oxygen deficiency in the grain interior. No variation of the intragrain critical current density with temperature is observed up to 85 K in a textured specimen.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::6aa3967cbddadfa09797cc43b46280ea https://doi.org/10.1016/0011-2275(88)90148-8 Zobrazit plný text záznamu