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arXiv · cond-mat/9507124

Intercalation and Staging Behavior in Super-Oxygenated $La_2CuO_{4 + δ}$

B. O. Wells·R. J. Birgeneau·F. C. Chou·Y. Endoh·D. C. Johnston·M. A. Kastner·Y. S. Lee·G. Shirane·J. M. Tranquada·K. Yamada
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Abstract

A high temperature electrochemical oxidation process has been used to produce large single crystals of $La_2CuO_{4 + δ}$ suitable for neutron scattering experiments. Below room temperature the oxygen-rich phases have structural superlattice scattering peaks which indicate new periodicities ranging from 2 to 6.6 layers perpendicular to the copper oxide planes. A model structure originally proposed for $La_2NiO_{4 + δ}$ 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 $La_2CuO_{4 + δ}$ as a unique lamellar superconducting system with annealed disorder.

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B. O. Wells, R. J. Birgeneau, F. C. Chou, Y. Endoh, D. C. Johnston, M. A. Kastner, Y. S. Lee, G. Shirane, J. M. Tranquada, K. Yamada. 1995-07-27. Intercalation and Staging Behavior in Super-Oxygenated $La_2CuO_{4 + δ}$. https://doi.org/10.1007/s002570050158

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