On the Nature of Superconducting Precursors in Bi-Pb-Sr-Ca-Cu-O Compositions Fabricated by Hot Shock Wave Consolidation Technology

Abstract

In this paper, the possibility of critical temperature increasing of superconducting precursor Tс and the current bearing capacity in samples of Bi-Pb-Sr-Ca-Cu-O superconducting system fabricated using hot shock wave consolidation (HSWC) technology and investigated by the vibrating torsional magnetometry method, was studied. The advantage of HSWC technology over the traditional technologies of superconducting composites synthesis is that the high-density materials are made from the Bi-Pb-Sr-Ca-Cu-O superconducting system. After the action of explosive wave the superconductivity is retained. After the explosion a pronounced texture is formed indicating the creation of efficient pinning centers and thus, the increase of current-carrying ability of the obtained material. The critical temperature of potential superconducting precursor Tc of transition to superconducting state increased from Tc=107K for starting sample to Tc=138K, using the HSWC technology for synthesis of samples in range of pressures from P=5GPa up to P=12GPa.

Superconducting Precursors in Bi/Pb Multiphase Cuprates Fabricated by the Solar Technology and their Comparative Study by Torque Magnetometry Methods

“…To determine the phase composition of the samples, a diffractometer (DRON-UM1, Cu Kα radiation, Ni filter) and a microscope (NU-2/E, Carl Zeiss Jena, Germany) were used. To determine the critical temperatures of the superconducting transition T c of these samples, the original vibrating torsional magnetometry method was used to study the torsion oscillations of samples in an applied magnetic field, realized using an automated multipurpose device [6] having a sensitivity comparable to that of a SQUID magnetometer. The appearance of pinned vortices produces a non-zero magnetic moment M in the sample.…”

“…Measurement methods are continueously being improved. To determine the critical temperatures of the superconducting (SC) transitions T c of these samples obtained by this technology, the original torsional oscillation magnetometry method in applied magnetic fields was realized using an automated multipurpose device [6], which has a sensitivity comparable to that of a SQUID magnetometer. In [7][8], the potential possibilities of the Vibrating Reed (VR) magnetometry method for similar purposes were also investigated.…”

Vibrating Reed Study of Superconducting Cuprates Fabricated by Superfast Melt Quenching in a Solar Furnace

“…The location of the coils in the immediate vicinity of the sample allows the creation of a sufficiently strong alternating field on it by using a standard low-frequency generator. The alternating field h created by the Helmholtz coils can also be directed at different angles that were combined with application of solar energy and superfast quenching melt technology [1][2][3][4][5]. Amorphous precursors and their use make possible the manufacturing of high-density low porous texturized ceramics with given dimensions of grains.…”

“…From this point of view, particular interest attracts the Bi-Pb-Sr-Ca-Cu-O system, because it is characterized by high Т с =107К and the record high second critical magnetic field Н с2 ~150T. Our group has undertaken research on the possibility to increase the Т с of this system [1][2][3][4][5]. In [1][2][3]5] the melt technology for obtaining Bi-Pb-Sr-Cu-O HTSC ceramics using solar energy for melting and subsequent superfast melt quenching for increasing of internal inhomogeneities was developed, allowing the receiving of homogeneous, highquality, textured ceramic samples with controllable microstructure and pinning centers.…”

“…In [1][2][3]5] the melt technology for obtaining Bi-Pb-Sr-Cu-O HTSC ceramics using solar energy for melting and subsequent superfast melt quenching for increasing of internal inhomogeneities was developed, allowing the receiving of homogeneous, highquality, textured ceramic samples with controllable microstructure and pinning centers. In [4], Hot Shock Wave Consolidation Technology was used to produce Bi-Pb-Sr-Ca-Cu-O compositions with increased internal inhomogeneity and for studying their superconducting precursor phases by torsional magnetometry method. This time, for increasing internal inhomogeneity we used solar melting and following superfast quenching technology.…”