Effect of Na substitution and Ag addition on the superconducting properties of Bi-2212 textured materials


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ÖZÇELİK B., NANE O., Sotelo A., AMAVEDA H., Madre M. A.

JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS, vol.28, no.8, pp.6278-6283, 2017 (SCI-Expanded) identifier identifier

Abstract

The effect of Ag addition on the structural and superconducting properties of Bi2Sr2Ca0.925Na0.075Cu2Oy + x wt% Ag materials with x = 0, 1, 3, and 5 prepared by sol-gel method, followed by directional growth using the laser floating zone (LFZ) technique has been investigated. Powder XRD measurements demonstrate that all samples are composed by nearly single Bi-2212 phase. SEM micrographs and EDX results confirms that Bi-2212 is the major phase with minor amounts of a Bi-free one (Sr,Ca)CuO2 and metallic Ag. According to the magnetic results, Ag does not modify the superconducting critical temperature, T (c) , but significantly increases the magnetic hysteresis loop area. The magnetic critical current density is maximum in the 3 wt% Ag containing samples, due to the larger grain clusters found in these samples, reaching 2.1 x 10(5) A/cm(2) at 10 K. Moreover, Ag addition also improves the rods mechanical properties, determined by three point bending tests. The highest bending stress is also reached in the 3 wt% Ag samples.