Obtenção e caracterização de supercondutores de Bi2212 texturizados com introdução de centros artificiais de aprisionamento / Production and characterization of textured Bi2212 superconductors with introduction of artificial pinning centers.

AUTOR(ES)
FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

10/09/2010

RESUMO

The present work analyzed the texturing conditions of Ag/Bi2212 samples (Bi2Sr2CaCu2O8+δ) in the form of bulks and of tapes, verifying the influence of heat treatment, atmosphere, silver addition and addition of zirconia or calcium zirconate. The additions of zirconia or calcium zirconate, with particles of submicron or nanometric (below 200nm) dimensions, were analyzed as possible generators of magnetic flux pinning centers, as well as it was analyzed their behaviors on the intrinsic properties of the superconducting matrix. The influence of the heat treatment atmosphere was analyzed in order to change the oxygen concentration in the superconducting phase aiming better results of critical temperature, without depreciation of the critical current densities and of the irreversibility fields, Birr. The influences of the heat treatment parameters were analyzed, such as the reaction maximum temperature, soaking time at this maximum temperature, cooling rate from the liquid to the solid states, and annealing temperature and time after solidification. It was verified the influence of the furnace cooling rate on the texturing and critical temperatures. Concerning to the silver addition, it was verified its influence on the texturing and its interaction with the zirconia. Superconducting and microstructural characterizations of the samples were performed.

ASSUNTO(S)

artificial pinning centers centros artificiais de aprisionamento difratometria de raios x microscopia eletrônica de transmissão microscopia eletrônica de varredura scanning electron microscopy superconductivity supercondutividade transmission electron microscopy x-ray diffractometry

ACESSO AO ARTIGO

Documentos Relacionados