<正> 近一年来,在Ba(Sr)-La-Cu-O体系中,陆续发现了一系列高Tc(30—40K)超导体。最近的报道表明,有关超导材料的研究呈现日新月异的飞速进展。本文报道一种起始转变温度为
The supercoductivity and structure of Y-Ba-Cu oxide have been investigated by means of electrical resistance and magnetic susceptibility measurements as well as X-ray diffraction, SEM and electron probe microanalysis. The results show that the onset temperature is 107.6K and the zero resistivity state occures at 94.8K with a width of about 2K for the sample of Ba_3Y_2Cu_5O_(5(3-z)). Diamagnetic susceptibility (Meissncr effect)was observed by magnetic susceptibility measurement, and confirmed with electrical resistance determination. The specimen consists mainly of hexagonal (or rhombohedral) ABO_3-type phase with lattice parameter of a=b=0.550nm, c=1.332nm and space group of R3c of R3m. The particles of oxide well connecte up each other, although quite a large number of pores exist. Zero resistance can be kept while up to 2A/cm~2 current passes through the sample.
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