Gold diffusion in superconducting Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy was investigated at

500 to 800C by using the energy dispersive X-ray fluorescence technique. It was

found that the Au diffusion coefficient decreased as the diffusion-annealing

temperature decreased. The temperature dependences of Au diffusion coefficient in

grains and over grain boundaries were described by:

D1 = 6.7 x 10−5exp[−1.19(eV)/kT]

and

D2 = 9.7 x 10−4exp[−1.09(eV)/kT]

respectively. The diffusion doping of Bi-2223 by Au causes a significant increase

of the lattice parameter c by about 0.19%. For the Au-diffused samples, dc

electrical resistivity and transport critical current density measurements indicated

the critical transition temperature increased from 100 to 104K and the critical

current density increased from 40 to 125A/cm2, in comparison with those of

undoped samples. From scanning electron microscope and X-ray diffraction

measurements it was observed that Au doping of the sample also improved the

surface morphology and increased the ratio of the high-Tc phase to the low-Tc

phase.

EDXRF Measurements on Gold Diffusion-Doped Bi1.8Pb0.35Sr1.9Ca2.1Cu3Oy.

C.Terzioglu: Physica B, 2008, 403[18], 3320-5