ISSN:
1573-482X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Electrical Engineering, Measurement and Control Technology
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Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The temperatures and sequence of formation of superconducting phases within the composition Bi1.6Pb0.4Sr2Ca2Cu4O x were determined using simultaneous differential thermal analysis (DTA) and thermogravimetric analysis (TGA), X-ray powder diffraction (XRD) and scanning electron microscopy (SEM). A single phase high-T c ceramic was obtained by a solid state reaction using predetermined firing conditions, although a transmission electron microscopy (TEM) study showed a small amount of glass phase in the grain boundary tripoint regions. The unit cell of the high-T c phase was refined asa=0.5413 nm,b=0.5414 nm,c=3.715 nm. The melting temperature of the high-T c phase is in the region of 852–862°C. The effect of lead was believed to lower the temperature of formation of the high-T c phase. Lead was also found to evaporate from the matrix during and after high-T c phase formation, whereas bismuth was found to be stable in both the low-T c phase and high-T c phase compounds.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00696074
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