Effect of Ag₂O addition on the intergranular properties of the superconducting Bi (Pb) Sr Ca Cu O system

Abstract

The effect of Ag2O addition on the Bi-(Pb)-Sr-Ca-Cu-O system has been investigated in terms of ac susceptibility, phase evolution, critical current density and critical temperature. It was found that as the amount of Ag2O addition increases, the intergranular critical current density decreases in our samples (Bi1.84Pb0.34Sr1.91Ca2.03Cu3.06O10) fabricated by ammonium nitrate technique. The analysis for comparison is based on the suppression degree of the diamagnetic behaviour with respect to fields, rapid or slow shift of the summit in χ'(T) to lower temperature with increasing field amplitude and the sharpness of the transition of χ'(T) for intergranular component for the same field amplitude. We also qualitatively discuss experimental results in the framework of the critical state model. The room temperature XRD diagram indicates the presence of large amount of high-Tc (2223) phase. The percentage of Bi-2223 phase in the phase mixture was estimated from the intensities of high-Tc (2223) and low-Tc (2212) phase peaks as 78% for the pure BSCCO sample. Among the Ag2O-added BSCCO samples studied, the one in which 5 wt%Ag2O was added shows the highest rate of Bi-2223 formation as 92%. The SEM analysis reveals some morphological changes induced by silver addition.

Vickers hardness measurements and some physical properties of Pr2O3 doped Bi-2212 superconductors

“…In particular, Bi-Sr-Ca-Cu-O (BSCCO) superconductor materials discovered by Maeda et al [5] have widely been investigated owing to the fact that the interest in both the fundamental research and applications in technology and industry of these materials in the last decades stems from their remarkable smaller power losses, high current and magnetic field carrying capacity, optical and electronic properties [6][7][8][9][10][11][12][13][14]. The BSCCO system obtaining a layered structure has three different phases with respect to its chemical compositions, the Bi-2201 phase (n = 1, Tc & 20 K), the Bi-2212 phase (n = 2, Tc & 85 K) and the (Bi, Pb)-2223 phase (n = 3, Tc & 110 K) [15].…”

Ion Beam Analysis and Electrical Resistivity Studies of (Cu0.5Tl0.5)-1223 Phase with Added Nano-oxides

“…Only small amounts of secondary phases appeared, such as (Cu 0.5 Tl 0.5 )-1212 and BaCuO 2 phases. The volume fraction, for all the prepared samples, are calculated using all the peak intensities of (Cu 0.5 Tl 0.5 )-1223, (Cu 0.5 Tl 0.5 )-1212 and BaCuO 2 phases [29] and are listed in Table 1. It is obvious that the volume fraction of the main phase, (Cu 0.5 Tl 0.5 )-1223, increases with nano-SnO 2 addition up to x = 0.6 wt% afterwards, it retards for x = 1.0 wt%.…”

Effect of Magnetic Field Direction on Magnetoresistivity, Activation Energy, Irreversibility and Upper Critical Field of Bi-2212 Thin Film Fabricated by DC Sputtering Method

“…Therefore, the researchers have attempted to improve the superconducting, mechanical, structural and flux pinning properties of the superconductors to make them suitable for high temperature and magnetic field applications [1][2][3][4]. The Bi-Sr-Ca-Cu-O (BSSCO) materials, one of the cuprate high-temperature superconductor families, have widely been investigated because of their higher critical temperature, remarkable smaller power losses, higher current and magnetic field carrying capacity, optical and electronic properties [5][6][7][8][9][10][11][12][13]. Moreover, in the literature there have been several reports relating to BSCCO films for high frequency applications including filters, antennas and magnetic shield devices [14][15][16][17].…”