ar X iv : c on d - m at / 9 50 71 24 v 1 2 7 Ju l 1 99 5 Intercalation and Staging Behavior in Super - Oxygenated
نویسندگان
چکیده
A high temperature electrochemical oxidation process has been used to produce large single crystals of La 2 CuO 4+δ suitable for neutron scattering experiments. Below room temperature the oxygen-rich phases have structural superlattice scattering peaks which indicate new period-icities ranging from 2 to 6.6 layers perpendicular to the copper oxide planes. A model structure originally proposed for La 2 NiO 4+δ can account for the superlattice peaks as a result of anti-phase domain boundaries between different tilt directions of the CuO 6 octahedra. Within this model, the changes in CuO 6 tilt directions are induced by segregated layers of interstitial oxygen which order in a manner similar to intercalants in graphite. This structural model thus clarifies previous work and establishes La 2 CuO 4+δ as a unique lamellar superconducting system with annealed disorder.
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ar X iv : c on d - m at / 9 50 80 62 v 1 3 1 Ju l 1 99 5 QUANTUM THEORY OF LARGE SYSTEMS OF NON - RELATIVISTIC MATTER
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