Ahmed S. Mahmoud

• Doctor of Philosophy
• Faculty Member at University of Tripoli

The effect of Nd <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3.6</sub> Ba <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2.4</sub> Cu <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">1.8</sub> O <sub xmlns...

The vortex dynamics of (Y, Nd)Ba2Cu3O7−δ ((Y, Nd)123) superconductors have been studied using magnetic relaxation measurements obtained at different sweep rates. The temperature dependence of the dynamic relaxation rate (Q) is found to be not vanishing at T = 0 K, and also showed well developed maxima becoming broader and tending to move to hi...

Magnetic hysteresis loops for the superconductor (Y, Nd)Ba2Cu3O7-δ have been measured using a SQUID and a vibrating sample magnetometer. The field dependence of the current density and volume pinning force showed well developed maxima and their temperature-dependent characteristics were used to construct different scaling types. The measurement of...

Using a high resolution magneto-optical technique, flux motion along the twin planes of a high quality YBa2Cu3O7-delta single crystal was systematically studied when an external magnetic field was applied along the c-axis of the crystal. Our results support the concept that whether or not the twin planes act as a barrier or a channel for vortex mot...

Flux-pinning in Y0.5/Nd0.5 (123) melt-textured growth sample that had been doped with excess 20wt.% Y1/Nd1(211) and 0.5 wt.% PtO2 has been analyzed by means of a scaling approach. The different parameters of scaling, irreversibility field (B.irr), magnetic field (Bjp) and current density(Jp) of the fishtail peak effect, and the field (Bfp) correspo...

The effect of Y1/Nd1(211) additions on the microstructure and superconducting properties of the Y0.5/Nd0.5 (123) system was investigated using a melt-processing technique in air. The microstructure investigation revealed a significant preference for Nd to dominate the Re site of the 123 phase with a similar trend for Y to dominate the Re site of th...

The effect of Nd2O3, BaCO3, Nd(422), Y1/Nd1(211) and PtO2 dopants on the microstructure and superconducting properties of melt-processed Y0.5/Nd0.5(123) has been studied. Within measurement error, each sample showed no evidence for Nd3+ substituting on Ba2+ sites. Microstructural analysis indicated that enriching the starting composition, Y0.5/Nd0....

Large crystals have been grown by a melt-processing technique from material with the starting composition that had been doped with , Pt and . The crystals have been investigated using a number of different techniques and for the undoped and those doped with Y/Nd(211) and/or Pt there is no evidence for substituting on sites. Crystals doped with show...