Superconductivity in a Ge-doped Bi-Pb-Sr-Ca-Cu-O system

Abstract: 

The effect of the substitution of Ge in the Bi16. Pbo.4Sr2Ca2Cu, _, Gex, Oy, system has been investigated by means of x-ray diffraction and electrical resistivity measurements. The volume fraction of the 2223 phase Is found to decrease with increasing Ge concentration. The lattice parameter c of the 2223 phase decreases slightly with increasing Ge concentration. The onset of the superconducting transition is about 110 K for all samples. The temperature of zero resistivity, however, is suppressed with Go substitution. The superconductivity of the 2212 phase is evident only for x = 0.5. There is evidence of weak links between the grains. The ratio of the extrapolated residual resistivity to the normal-state resistivity Increases with increasing Ge concentration Indicating that the disorder in the system increases with x.

 

Authors: 

Nkum, R. K.(  College of Science, Professor, Provost, rknkum.cos@knust.edu.gh, 0322060313) 
Datars, W. R.

 

Place of publication: 

This is Nkum's and Datar's article published, 2011.

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