Impact of Nano-Sized Diluted Magnetic Semiconductors Addition on (Cu,Tl)1234 Superconducting Phase

The effect of Zn_0.95Ni_0.05O nanoparticles addition on the superconducting properties of (Cu_0.25Tl_0.75)Ba₂Ca₃Cu₄O_12−δ superconducting phase was studied. Superconducting samples of type (Zn_0.95Ni_0.05O)_x(Cu_0.25Tl_0.75)Ba₂Ca₃Cu₄O_12−δ, x = 0.0, 0.2, 0.4, 0.6, 0.8, and 1.0 wt%, were prepared via a single step of solid-state reaction technique at 850 °C under ambient pressure. X-ray powder diffraction, scanning electron microscope, and energy dispersive X-ray were used for samples characterization. The superconducting properties were investigated using the electrical resistivity and DC magnetization measurements. The results showed that the addition of nano-Zn_0.95Ni_0.05O up to x = 0.6 wt% enhanced the phase formation and improved the superconducting transition temperature T_c in contrary for x > 0.6 wt%, T_c was decreased as x increased. Low field magnetization measurement, H = 20 Gauss, was conducted to the samples to determine the magnetic superconducting transition temperature T_c-mag. Both T_c and T_c-mag were found to have the same behavior with increasing x, whereas the values of T_c-mag were slightly lower than that for T_c values.