Superconductivity of BSCCO Compound Substituted Partially by Zr Nanoparticles at Bi Site

High-temperature superconductors with a nominal composition Bi2- xZrxPb0.4Sr2Ca2Cu3Oy for (0≤x≤0.3) were prepared by solid-state reaction method. Effects of the Zr nanoparticles substitution at Bi sites have been studied to obtain the optimum concentration for the formation and stabilization of the superconducting samples. Electrical resistivity measurements of the samples showed that the higher critical temperature TC was found at 118 K, which is for the composition Bi1.95Zr0.05Pb0.4Sr2Ca2Cu3Oy. Semiconductor behavior noticed for samples with concentration higher than 0.2. The X-ray diffraction results for all superconducting samples showed an orthorhombic structure with two phases, 2223 high-TC phase and 2212 low-TC phase. The scanning electron microscope has been used to identify the morphology of the superconducting phase. The plate-like grains of the high Bi-2223 phase appeared in most samples besides changes in morphology of the samples with increasing dopant concentration

Superconductivity Measurements of (Hg,Tl)-1223 Compound Prepared in Capsule

In this paper, investigations were carried out on the effects of simultaneous partial substitution of Tl at the Hg site on the physical properties of an Hg1-xTlxBa2Ca2Cu3O8+δ cuprate superconductor with x= 0, 0.1, 0.2, 0.3 and 0.4. Two steps of the solid state reaction method were used to prepare samples in capsule. The results showed that the optimum sintering temperature was equal to 850 ᵒC and the sintering time was equal to 20 h for the prepared samples. The best conditions for constitution and stabilization of the high Tc phase-1223 were obtained by investigating the effects of Tl substitution on Hg site and oxygen content (δ) on the superconducting properties. Structural investigation revealed that all the samples have a tetragonal structure with two phases, namely an Hg-1223 high Tc phase as a main phase and an Hg-1212 low Tc phase. Besides, some impurity phases like CuO and CaHgO2 were found. The increase of Tl content in Hg1-xTlxBa2Ca2Cu3O8+δ compound from 0 to 0.4 caused a change in the lattice parameter, density of the unit cell (ρm), and c/a values. HgBa2Ca2Cu3O8+δ compound exhibited a critical transition temperature that is equal to 115 K. On the other side, the results showed that the highest Tc was 119 K for Hg0.8Tl0.2 Ba2Ca2Cu3O8+δ. The oxygen content (δ= 0.46) was expected to be the optimum hole doping for Hg0.8Tl0.2 Ba2Ca2Cu3O8+δ compound, which means in our opinion that δ plays a remarkable role in the assessment of Tc.

Structural and transition tempreature of HgPb

solid state reaction technique (SSR) was used to prepare high-Tc phase in superconductors the effect of additional Pb to was investigated it has been found

Study Effect of annealing Temperature on enhancement of High-Tc Phase for BiPbSrCaCuZnO thin film through thermal expantion

Annealing thermal plays an important role on the formation of high Tc-phase BiPbSrCaCuZnO through expansion and contraction layers which be associated with formation high and low phases respectively, The prepared samples composition BiPbSrCaCuZnO have been annealed at (820,840,860,880) C°. It is observed the critical temperature Tc increase for films which annealed at (820,840,880) C°while Tc decreases at Ta =860 C°.

Synthesis and study the Structural and electrical and mechanical properties of High Temperature Superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ Substituted with nickel oxide for n=3

on this research is to study the effect of nickel oxide substitution on the pure phases superconductor Tl0.5Pb0.5Ba2Can-1Cun-xNixO2n+3-δ (n=3) where x=(0,0.2,0.4,0.6,0.8.and 1.0). The specimens in this work were prepared with used procedure of solid state reaction with sintering temperature 8500C for 24 h .we used technical (4-prob)to calculated and the critical temperature Tc . The results of the XRD diffraction analysis showed that the structure for pure and doped phases was tetragonal with phases high-Tc phase (1223),(1212) and low-Tc phase (1202) and add to the presence of some impure phase. It was noted the value a=b,c the parameter of the lattice increment with the increment of Ni content. The increment of (NiO) concentration effects electrical resistivity, dielectric constant and the hardness.

Effect of Sb2O3 and/or CdO nanoparticle substitution on the properties of high-TC superconducting Bi1.6-x SbxPb0.4Sr2Ca2-yCdyCu3OZ material

High temperature superconductors materials with composition Bi1.6-xSbxPb0.4Sr2Ca2-yCdyCu3OZ (x = 0, 0.1, 0.2 and 0.3) and (y = 0.01 and 0.02), were prepared by using the chemical reaction in solid-state ways, and test influence of partial replacement of Bi and Ca with Sb and Cd respectively on the superconducting properties, all samples were sintered at the same temperature (850 oC) and for the same time (195 h). The structural analysis of the prepared samples was carried out using X-ray diffraction (XRD) measurements performed at room temperature, scanning electron microscope (SEM) and dc electrical resistivity was measured as a function of temperature. It was found that the sample prepared by partial substitution of Sb at ratio (x= 0.2) and Cd with ratio (y=0.01), has the maximum value of zero resistance temperature, where was the TC(onset) and TC(0) values for this sample are (140 K) and (123 K) respectively, and XRD results reveal that this sample has the highest percentage of Bi- 2223 phase, as well as the analysis of XRD patterns of the prepared materials showed polycrystalline structure and signalize that all samples had an orthorhombic crystalline structure. It was concluded that Sb2O3 nanoparticles it may be acts as a flux agent in the matrix to lower the partial melting temperature of the samples and that leads to the promotion of the high-TC phase.