MAGNETIC ORDER, SPIN CORRELATIONS, AND SUPERCONDUCTIVITY IN SINGLE-CRYSTAL ND1.85CE0.15CUO4+DELTA
MAGNETIC ORDER, SPIN CORRELATIONS, AND SUPERCONDUCTIVITY IN SINGLE-CRYSTAL ND1.85CE0.15CUO4+DELTA
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DOI：
10.1103/physrevb.45.12548
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发表时间：
1992-06-01
影响因子：
3.7
通讯作者：
SHIRANE, G
中科院分区：
文献类型：
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作者：
MATSUDA, M;ENDOH, Y;SHIRANE, G
报道了Nd1.85Ce0.15CuO4+单晶的静态、瞬时和动态自旋关联的测量结果。生长的晶体具有反铁磁长程有序结构。然而，在Nd2CuO4+Delta中，Neel温度和自旋刚度常数比它们各自的值大大降低。经还原和退火后，T(C)=23K的晶体具有超导性，但始终存在反铁磁相的包裹体，尽管Neel温度降低。基于这些数据，我们认为在生长的样品中由于过量的氧引起的无序稳定了磁关联。这导致了一个关于脱氧效应的推测模型，在该模型中，去除多余的氧气会导致磁关联减弱，从而使超导成为可能。
Measurements are reported of the static, instantaneous, and dynamic spin correlations in single crystals of Nd1.85Ce0.15CuO4+delta. The as-grown crystals show antiferromagnetic long-range order. However, the Neel temperatures and spin-stiffness constants are greatly reduced from their respective values in Nd2CuO4+delta. After reduction and annealing, the crystals superconduct with T(c) = 23 K, but inclusions of the antiferromagnetic phase, albeit with reduced Neel temperatures, are always present. Based on these data, we suggest that the disorder due to excess oxygen in as-grown samples stabilizes the magnetic correlations. This leads to a speculative model for the effects of deoxygenation in which the removal of the excess oxygen causes the magnetic correlations to diminish and hence superconductivity to become possible.