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High-quality fibrous crystals have been grown by prolonged heating of amorphous plates in an oxygen flow. The whisker growth rate was varied between 0.005 and 0.1 mm h-'. The crystals obtained at high temperature had frozen liquid droplets. The body of the whiskers had reasonably constant composition, which did not correspond to the droplet composition. The growth of the fibres occurred by liquid-phase transport of Ca and Cu along the crystal from the amorphous plate to the crystallization zone. This mechanism is termed growth via melt transport under a temperature gradient (MTTG). T,, J, and gap parameter, A, values for several whiskers were measured. The highest J, value (2 x lo5 A cm-* at 77 K) and the highest T, value were achieved in (2212 +2223) interlayered fibres.A fundamental feature of Bi2Sr2Ca,-,Cu,02,+, (n = 1-3) superconducting crystals is their high anisotropy and a pronounced tendency for crystal growth in the ab plane. This is why Bi-Sr-Ca-Cu-0 (BSCCO) crystals acquire only platelike or whisker-like forms.lT2 For a better understanding of the structural and physical properties of single crystals it is desirable to obtain perfect single crystals, like whiskers, which are especially attractive for precise investigation^.^-^ The ability of BSCCO compounds to form a solid solution with a wide range of compositions yields a promising potential for whisker-like fibres modifications. However, the mechanism of formation and the main factors responsible for the growth of the crystals and their shape are not well This paper describes specific whisker-like fibre growth experiments under varying conditions of precursor plate composition, temperature, oxygen flow rate and temperature gradient. The cation composition, morphology, structural parameters and superconducting properties of the whiskers obtained have been investigated. The most probable model of whisker growth has been proposed.

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were prepared by t h e method of annealing and cold rolling cycles on Au, Ag. and Ni with silver sublayer substrates with T, (zero) = 92, 101, and 99 K respectively. The films obtained consisted of a mixtureof 2212 and 2223 phases. The T, of these films increased during annealing at an ambient temperature of 830% with IowP,, for up to 200 h. It was shown by emanation thermal analysis that on heating in air, the liquid phase appears in t h e superconductor at 840°C and, on contact with silver, at 830°C. Heating in an argon atmosphere (Po2 = 5 kPa) reduces these values to815"C and 800°C respectively. No appreciable chemical interaction was noticed. W e present t h e results of an Ag sublayer on Ni thickness calculations, based on diffusion and solubility parameters.