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Bi2-Xhgxsr2-Ybaycacu2o8/Ag Sheath
HTSCWires, (Hg, Ba) Substitution Effect on he Critical
Temperature |
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Bi2-xHgxSr2-yBayCaCu2O8 High
Temperature Superconductor (HTSC) has been prepared as a pellet
by solid state reaction with a certain substitution percentages
(0 ,0.05 ,0.1) of Hg and Ba substitution instead of Bi and Sr
respectively . Then, HTSC wires were fabricated from the
prepared superconductor pellets using powder in tube (PIT)
method utilizing silver as the tube material. The prepared wires
are of three types; with monofilament MOF, 9 multifilament core
9MF and 81 filaments core(81MF). Several cycles of mechanical
drawing and rolling process performed to the starting silver
tube of 0.4 cm diameter and 5 cm length to minimize the filament
diameter. The average filament diameter with 81MFC wire was
about 25μm measured with an optical microscope. Tc critical
temperature for superconductivity is measured for the pellets
and wires using four point probes techniques. These results show
that the substation Bi by Hg give a rise to the superconductor
to improve highly Tc , while substitution Sr with Ba lowers Tc
.substitution of 0.05 , 0.1 Hg to the composition
Bi2-xHgxSry-2BayCa1Cu2O8 will raise the transition temperature
(Tc) . Also substitution of Sr by Ba decreases the transition
temperature (Tc), Hg( 0.05 – 0.1 ) substitution still raise Tc
after substitution of Ba with (0.05 – 0.1). low – Tc phase
(2212) , 2201 phase in B-2212 system and the addition of Ag to
silver sheaths and a small amount of impurity phases appear in
the result of XRD analysis. |
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