Abstract
We report on magnetic and structural neutron-diffraction studies of single-crystal versus temperature. The low-temperature diffraction data are consistent with the coexistence of two structurally related phases: nearly stoichiometric, antiferromagnetic (AF) domains, with average domain diameter ∼500 Å in the plane, and oxygen-rich, metallic, and superconducting domains. The ordered magnetic moment in the AF domains does not saturate at 10 K, and is on average, μ=(0.3±0.05)/Cu atom. The phase-separation transition to these two phases occurs at =260±5 K, which is about 15 K higher than the Néel temperature, =245±3 K. The value of is identical within the errors with that (259±2 K) found previously from specific-heat measurements on the same crystal. The structural properties of the single crystal are discussed and compared to those of polycrystalline oxygen-rich .
- Received 16 November 1993
DOI:https://doi.org/10.1103/PhysRevB.49.9057
©1994 American Physical Society