The properties of quenched Bi-Ca-Sr-Cu oxide superconductors
D P Almond; B Chapman; G A Saunders; D P Almond; Sch. of Phys., Bath Univ., UK; B Chapman; Sch. of Phys., Bath Univ., UK; G A Saunders; Sch. of Phys., Bath Univ., UK
Журнал:
Superconductor Science and Technology
Дата:
1988-10-01
Аннотация:
It has been found that samples of Bi-Ca-Sr-Cu oxide quenched from furnace temperatures in the range 820 to 895 degrees C exhibit resistive transitions and the development of a strong Meissner effect at 90 K. Weight loss measurements indicate a decline in oxygen content across the above temperature range. This significantly affects normal-state resistivity and raises T<sub>c</sub> to 90 K. Little variation in superconducting properties has been found across the wide range of quenching temperatures investigated. X-ray diffraction studies reveal lattice spacing differences in quenched and annealed samples but no anisotropy in the expansivities of their lattice spacings, indicating that interatomic binding forces have similar strengths in the a and c directions.
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