POSSIBLE HIGH-TC SUPERCONDUCTIVITY IN THE BA-LA-CU-O SYSTEM
POSSIBLE HIGH-TC SUPERCONDUCTIVITY IN THE BA-LA-CU-O SYSTEM
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DOI：
10.1007/bf01303701
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发表时间：
1986-01-01
期刊：
影响因子：
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通讯作者：
MULLER, KA
中科院分区：
文献类型：
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作者：
BEDNORZ, JG;MULLER, KA
Ba-La-Cu-O系统中的金属、缺氧化合物，其组成为La 5-xCu 5 O 5（3-y），已被制备成多晶形式。x =1和0.75，y>0的样品，在还原条件下低于900°C退火，由三相组成，其中一相是类钙钛矿混合价铜化合物。在冷却时，样品显示电阻率线性降低，然后近似对数增加，解释为局部化的开始。最后，突然下降了三个数量级，这让人想起了超导的开始。在30 K范围内观察到最高的起始温度。高电流密度可显著降低该值。因此，它的结果部分地从双钙钛矿层的双相的性质，布特也可能从二维超导波动的一个阶段存在。
Metallic, oxygen-deficient compounds in the Ba−La−Cu−O system, with the composition BaxLa5−xCu5O5(3−y)have been prepared in polycrystalline form. Samples withx=1 and 0.75,y>0, annealed below 900°C under reducing conditions, consist of three phases, one of them a perovskite-like mixed-valent copper compound. Upon cooling, the samples show a linear decrease in resistivity, then an approximately logarithmic increase, interpreted as a beginning of localization. Finally an abrupt decrease by up to three orders of magnitude occurs, reminiscent of the onset of percolative superconductivity. The highest onset temperature is observed in the 30 K range. It is markedly reduced by high current densities. Thus, it results partially from the percolative nature, bute possibly also from 2Dsuperconducting fluctuations of double perovskite layers of one of the phases present.