The effect of suppression of antiferromagnetic order and charge stripes formation mechanism, by <$E roman Zn 3 d sup 10> (S = 0) substitution at <$E roman Cu 3 d sup 9> (S = 1/2) sites in CuO2; planes of <$E roman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 3 Cu sub 4 O sub {12 - delta}}> on superconductivity parameters is demonstrated. If antiferromagnetism and charge stripes have some role in bringing about superconductivity at a particular temperature, the doping of nonmagnetic Zn impurity would destroy it and hence the superconductivity. However we have observed enhanced superconducting properties with the increase of Zn doping in <$E roman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 3 Cu sub 4 O sub {12 - delta}}> superconductor. The decreased c-axis length with the increase of Zn doping improves interlayer coupling and hence the three-dimensional conductivity in the unit cell. The role of charge carriers in CuO2 planes of <$E roman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 3 Cu sub 4-y Zn sub y O sub {12 - delta}}> in bringing about superconductivity has also been explained.

We synthesized (CuO, CaO2, and BaO)y/<$Eroman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 2 Cu sub 3 O} sub {10- delta }> (y = 0,5 %, 10 %, 15 %) composites by solid-state reaction and characterized by x-ray diffraction, scanning electron microscopy, dc-resistivity, and Fourier transform infrared spectroscopy. Frequency and temperature dependent dielectric properties such as real and imaginary part of dielectric constant, dielectric loss, and ac-conductivity of these composites are studied by capacitance and conductance measurement as a function of frequency (10 kHz to 10 MHz) and temperature (78 to 300 K). The x-ray diffraction analysis reveals that the characteristic behavior of <$Eroman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 2 Cu sub 3 O} sub {10- delta }> superconductor phase and its structure is nearly undisturbed by doping of nanoparticles. The scanning electron microscopy images show the improvement in the intergranular links among the superconducting grains with increasing nanoparticles concentration. Microcracks are healed up with the inclusion of these nanoparticles and superconducting volume fraction is also increased. The dielectric properties of these composites strongly depend upon the frequency and temperature. The zero resistivity critical temperature and dielectric properties show opposite trend with the addition of nanoparticles in <$Eroman {Cu sub 0,5 Tl sub 0,5 Ba sub 2 Ca sub 2 Cu sub 3 O} sub {10- delta }> superconductor matrix.

Fluctuation induced conductivity (FIC) analysis on dc resistivity versus temperature data of as-prepared and oxygen post-annealed <$Eroman {TlBa sub 2 (Ca} sub 2-y {roman Mg} sub y ) Cu sub 3 O sub {10- delta }> (y = 0, 0,25, 0,5, 0,75, 1,0) superconductor samples are carried out by using Aslamazov - Larkin model for excess conductivity. The microscopic parameters such as zero temperature coherence length along c axis {<$Exi sub c (0)>}, interlayer coupling (J), intergrain coupling (<$Ealpha>), critical exponent (<$Elambda>) and dimensionality of superconducting fluctuations are calculated with the help of aforementioned model. The crossover temperature (To) is shifted towards higher temperature values with the increase of Mg contents up to y = 0,5 and then start to decrease but still remains greater than those values of undoped samples. The increase in <$Exi sub c (0)> and J after Mg-doping at Ca sites shows the improvement of interplane coupling in <$Eroman {TlBa sub 2 (Ca} sub 2-y {roman Mg} sub y ) Cu sub 3 O sub {10- delta }> samples. The appreciable change in all the microscopic parameters extracted from the FIC analysis indicates the optimization of oxygen in all the oxygen post-annealed samples. The increase in relative intensity of almost all the oxygen modes indicates the oxygen diffusion in the unit cell after oxygen post-annealing. The diffusion of oxygen can take place at intergranular sites along with intragranular sites, which increases the grains size, intergrain connectivity and carrier density in CuO2 planes.

Present study describes the atomic absorption spectro-photometric determination of metals (Ni, Cr, Zn, Fe, As and Cu) in the surface water of Lahore canal passing through the center of Lahore (city) Pakistan. Analysis showed that month wise average Ni, Zn and As concentrations lies within the National Environmental Quality Standards limits for these metals as designed by Environmental Protection Agency Pakistan, while Cr, Fe and Cu showed marked rise in their month wise average concentrations from their limiting values.

Ferromagnetic nickel (Ni) nanoparticles were added in <$E roman {(Cu sub 0,5 Tl sub 0,5 )Ba sub 2 Ca sub 2 Cu sub 3 O sub {10- delta}}> (CuTl-1223) superconducting matrix to get Nix/CuTl-1223; x = 0 - 1,00 wt % nanoparticles-superconductor composites. Temperature- and frequency-dependent dielectric properties of CuTl-1223 superconducting phase with different contents of Ni nanoparticles were studied. Different dielectric parameters such as dielectric constant (<$E {epsilon prime} sub r>, <$E {epsilon symbol Т} sub r>), dielectric tangent loss (tan <$E delta>) and ac conductivity (<$E sigma sub ac>) were determined from experimentally measured capacitance and conductance at different frequencies from 10 kHz to 10 MHz and at different operating temperatures from 78 to 290 K. The values of <$E {epsilon prime} sub r> and <$E {epsilon symbol Т} sub r> were found maximal at smaller frequencies and started to decrease at higher frequencies. The value of <$E sigma sub ac> is high at high frequency unlike to <$E {epsilon prime} sub r> and <$E {epsilon symbol Т} sub r>, which is due to release of space charges at high frequencies. Peaks in tan <$E delta> graphs represent the resonance phenomenon at certain frequencies in these samples. Non-monotonic behavior in variation of dielectric parameters with temperature of Nix/CuTl-1223 samples was observed particularly at high temperatures which was due to thermal instability of the system at high temperatures.