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Abstract

Nearly single phase superconducting samples of the general
formula (Bi/Pb)(2)(Sr2-xCax)(2)Cu3O10 were prepared by the
usual high temperature solid state reaction technique and
ceramic procedures. The prepared sample with x = 0.6, with
optimally nominal oxygen content (over doped) shows T-c of 107
K. The increase in T-c is also accompanied by an increase in
the room temperature c-axis length. The crystal structure of
the sample was determined by Cu-K, X-ray diffractometry. This
crystal belongs to a tetragonal system and has a space group of
14/mmm with a = 3 6732 Angstrom and c = 34.3176 Angstrom. The
TGA and DTA thermal analyses on the green samples included
steps of thermal decomposition of CuCO3 (300-400 degreesC).
CaCO3 (660-710 degreesC), SrCO3 (710-800 degreesC) and finally
to the high temperature solid state formation of
superconductive phase at 820 degreesC Finally a proposed
crystalline structure symbol was put forward. (C) 2002 Elsevier
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