Influence of pelletization pressure on the structural and transport properties of TlCaBaCuO superconductors

Abstract

An investigation is reported of the effects of pelletization pressure on the structural and transport properties of polycrystalline TlCaBaCuO samples with nominal composition of Tl2Ba2Ca2Cu3O10–x . The measurements reveal the following interesting results as the pelletization pressure increases: (1) the volume fraction of self‐formed Tl‐2212 phase decreases and the amount of target Tl‐2223 phase increases; and (2) the links between grains become stronger. Consequently, energy dissipation on grain boundaries decreases and critical current increases. The paper also discusses the applicability of thallium samples as magnetic field sensors. It was found that the samples pelletized at low pressures become more sensitive to a magnetic field compared to those pelletized at high pressures. (© 2008 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Effect of Compaction Pressure on Structural and Superconducting Properties of Bi-2223 Superconductors

“…It was also observed that the zero resistance temperature T c (off) increased and the transition width decreased with increasing pellet formation pressure. Transport critical currents of samples increased with increasing temperature as a consequence of improved intergranular couplings [7].…”

“…Beside Bi-based superconductors, Topal [7] have investigated the effect of compaction pressure on the structural and electrical properties of TlCaBaCuO superconducting materials. The porosity and the volume fraction of the Tl-2212 phase in the samples prepared with a nominal composition of Tl 2 Ba 2 Ca 2 Cu 3 O 10−δ were found to decrease and the Tl-2223 phase content increased with increasing compaction pressure in the above study.…”

Unexpected transport and magnetic properties in Y–Ba–Cu–O superconductors

“…One can see a small field dependence. On the other hand, the V – I characteristics of the oxygenated sample reveal that the logarithmic plots of the V – I data sets were found to be linear (above 10 µV), typical for polycrystalline HTSC 28 (Fig. 5b).…”