Development of TBCCO high temperature superconductor

Abstract

High Temperature Superconductor TBCCO-based cuprate material becomes an interesting material in cryogenic area since it has many superconducting phases. The improvements of this material have been made by atom substitutions as well as methods of preparation. The different number of CuO layers in Tl-based cuprate can be used to investigate the effect of different numbers of Cu–O layers as well as the role of agent doping in the mechanism of superconductivity in the cuprates. By using conventional method, the addition of Cr to (Tl1-xCrx) Sr2CaCu2O7-δ with x= 0.0, 0.05, ..., 0.20; critical temperature in the range of 91K to 105K. The (Tl1-xRhx) Sr2CaCu2O7-δ showed changes in room-temperature resistivity and sample with x = 0.20 showed the highest Tc-onset (91K). The electrical resistivity of (Tl1−xCrx) Ba2Ca2Cu3O9−δ for x = 0.4–0.8 samples showed Tc-onset at around 124K. Samples with nominal starting composition Tl2Ba2CaCu2O8 (CdTe)x with x = 0 to 0.20 weight percent (wt.%) have been prepared by the solid-state reaction method. The critical onset temperature, Tc-onset for all samples was between 104K and 108 K while the critical zero resistance temperature, Tc-zero was from 93K to 95K. It was found that the addition of nano Ag decreased the critical temperature and phase formation of (Tl0.85Cr0.15) Sr2CaCu2O7-δAgx. HTSC (Tl2-xCrxBa2CaCu2O8-δ) showed a Tc-zero of 96K and Tc-onset 116K for x = 2. Whereas a high Tc-zero of 100K and Tc-onset of 115K was found in (Tl1.9Te0.1Ba2CaCu2O8δ) system. Based on the most results of experiments, it can be concluded that TBCCO with toxic precursor is in high temperature superconductor. The presence of doping agent was effective only in a few moles. It was observed that phase formation affected the critical temperature.