Abstract
Measurements are reported of the static, instantaneous, and dynamic spin correlations in single crystals of Nd1.85Ce0.15CuO4+. The as-grown crystals show antiferromagnetic long-range order. However, the Néel temperatures and spin-stiffness constants are greatly reduced from their respective values in Nd2CuO4+. After reduction and annealing, the crystals superconduct with Tc=23 K, but inclusions of the antiferromagnetic phase, albeit with reduced Néel 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.
Original language | English |
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Pages (from-to) | 12548-12555 |
Number of pages | 8 |
Journal | Physical Review B |
Volume | 45 |
Issue number | 21 |
DOIs | |
State | Published - 1992 |
Externally published | Yes |