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

Abstract EN

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.