Superconductivity in Bi-Sr-Ca-Cu-O bulk samples made by thermal decomposition of metal oxalates

Critical temperatures and critical currents in sputtered thin films of Bi-Sr-Ca-Cu-O with varying O-concentration

“…For 1000 mbar oxygen, the temperatures mentioned above are x 10 "C higher. This observed decomposition of the n = l phase is similar to the reported behaviour of bulk material [8]. In the second step, the partial oxygen pressure was varied between 1000 mbar and mbar at a temperature Tz = GOO "C, obtained from a extrapolation of the DTA data.…”

Formation mechanism of the Pb free phase

“…A comparison of the XRD patterns obtained on the Pb free Bi(2223) phase [5,6,31,39,66] with those recorded on Pb substituted samples [15,84,85] usually shows that the (00l) reflections due to the Pb containing Bi, Pb(2223) phase are better defined, their FWHM typically lying around 0.15 • -0.30 • (in 2θ units) compared to about 0.6 • in the Pb free case.…”

“…The first traces of the Bi(2223) phase were detected by Maeda et al [30] in samples with a Bi 2 Sr 2 Ca 2 Cu 4 O y nominal composition. Although significantly richer in Cu than the idealized Bi 2 Sr 2 Ca 2 Cu 3 O 10 stoichiometry, this composition allowed the synthesis of relatively good quality samples (up to 80 vol.% Bi(2223)) [31]. Nevertheless, as with other nominal compositions containing large Cu and Ca excess (Bi 2 Sr 2 Ca 3 Cu 4 O y or even Bi 2 Sr 2 Ca 4 Cu 5 O y ) a non-negligible proportion of alkaline earth cuprates and unreacted CuO still remains in the sample [19,31,32].…”

“…Although significantly richer in Cu than the idealized Bi 2 Sr 2 Ca 2 Cu 3 O 10 stoichiometry, this composition allowed the synthesis of relatively good quality samples (up to 80 vol.% Bi(2223)) [31]. Nevertheless, as with other nominal compositions containing large Cu and Ca excess (Bi 2 Sr 2 Ca 3 Cu 4 O y or even Bi 2 Sr 2 Ca 4 Cu 5 O y ) a non-negligible proportion of alkaline earth cuprates and unreacted CuO still remains in the sample [19,31,32]. However, nominal compositions avoiding a Cu excess only rarely resulted in good quality samples as for instance in the case of Bi 2.09 Sr 1.95 Ca 1.90 Cu 3.00 O y [5,28].…”

Microwave preparation and sintering of industrially important perovskite oxides: LaMO3 (M = Cr, Co, Ni)

“…Because of their immense technological potential, 1-3 a number of methods have been developed to synthesize perovskite oxides. [4][5][6][7][8] Manganite perovskites of the general formula La 1 2 x A x MnO 3 (A ~Ca, Ba, Sr) have been prepared by Gibbons et al using the microwave route. 9 In this background we have developed a microwave method for the synthesis of perovskite oxides.…”