Growth of Bi-Sr-Ca-Cu-O based superconducting whiskers

Effect of Al2O3 additives on the formation of superconducting whiskers (2212 phase) in melt-quenched BiSrCaCu2Ox

“…8 The obtained samples at y = 0 and y = 0.2 were not glassy but devitrified, in which crystalline phases consist mainly of the 2201 phase and a small amount of Cu 2 O; the specimen at v = 0.5 was glassified. Matsubara et al 7 have pointed out that for the growth of whiskers it is necessary to use a glassy specimen as In the present work it was found by differential thermal analysis that the temperature of the endothermic peak due to the partial melting of the 2212 phase at around 870 °C shifts from 870 °C to 850 °C with increasing Al 3+ ion content; this lowering of the partial melting temperature may be a key to the whisker formation. So, the samples were poured onto a graphite plate and quenched by iron pressing.…”

“…4 Recently, Matsubara et al have investigated 2212 whiskers prepared by heating glassy melt-quenched plates of B i -S r -C a -C u -0 with doped elements such as Pb and Li. Matsubara et al 7 have pointed out that for the growth of whiskers it is necessary to use a glassy specimen as In this letter, we report on the effect of A1 2 O 3 additives to melt-quenched BiiSriCaiC^O^ on the formation of whiskers of the 2212 phase.…”

“…8 The obtained samples at y = 0 and y = 0.2 were not glassy but devitrified, in which crystalline phases consist mainly of the 2201 phase and a small amount of Cu 2 O; the specimen at v = 0.5 was glassified. Matsubara et al 7 have pointed out that for the growth of whiskers it is necessary to use a glassy specimen as So, the samples were poured onto a graphite plate and quenched by iron pressing.…”

Application of elevated magnetic fields during growth of BiSrCaCuO superconducting whiskers and studies of growth defects for better understanding of the growth mechanism

“…The same thermal regime ( Fig. 1) has been applied for the growth of whiskers by one-crucible method under high magnetic fields of 0, 7 and 10 T. Experimental arrangement and temperature profile on vertical [11][12][14][15][16][17][18] Bi-Sr-Ca-Al-O is developing into a rigid skeleton to support mechanically the bottom part of the whisker. Skeleton is surrounded by a thin layer of Bi-rich phase in the liquid state and having composition so that it is equilibrated with the Bi-2212 phase.…”

Whiskers

“…Upon the discovery of glass formation in the Bi -SrCa -Cu -O (BSCCO) superconducting system, efforts have been made to form whiskers of these materials via a glass-ceramic processing route. MATSUBARA and co-workers have successfully prepared whiskers of Bi 2 Sr 2 CaCu 2 O x , known as the 2212 phase, by heating glassy melt-quenched plates of the BSCCO system doped with Al [95], Li [96], and Ga in flowing oxygen. The phases, morphology, and superconductivity of the whiskers thus obtained depend greatly on the processing conditions and the type of dopant used.…”