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Advances in Condensed Matter Physics
Volume 2015, Article ID 873972, 5 pages
http://dx.doi.org/10.1155/2015/873972
Research Article

Chemical Reduction of Nd1.85Ce0.15CuO4−δ Powders in Supercritical Sodium Ammonia Solutions

1Department of Physics and Engineering Physics, Morgan State University, Baltimore, MD 21251, USA
2Department of Physics, University of Houston, Houston, TX 77204, USA
3State Key Laboratory for Mesoscopic Physics, School of Physics, Peking University, Beijing 100871, China

Received 14 December 2014; Revised 5 March 2015; Accepted 12 March 2015

Academic Editor: Markus R. Wagner

Copyright © 2015 Yasmin Dias et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Nd1.85Ce0.15CuO4−δ powders are chemically reduced in supercritical sodium ammonia solutions from room temperature to 350°C. The crystallographic structure of the reduced powders is investigated from Rietveld refinement of X-ray powder diffraction. The atomic positions are maintained constant within experimental errors while temperature factors of all atoms increase significantly after the chemical treatments, especially of Nd/Ce atoms. The ammonothermally reduced Nd1.85Ce0.15CuO4−δ powders show diamagnetic below 24 K which is contributed to the lower oxygen content and higher temperature factors of atoms in the treated compound. The ammonothermal method paves a new way to reduce oxides in supercritical solutions near room temperature.