Electron density distribution in Nd 2− xCe xCuO 4−δ

Abstract

The distribution of electron density in single crystals of Nd 2CuO 4 and changes caused by Ce doping in Nd 2− x Ce x CuO 4−δ crystals have been studied using X-ray diffraction data. Investigations have been carried out on a non-doped sample of Nd 2CuO 4 at 293 and 20 K, and on two crystals of Nd 2− x Ce x CuO 4−δ at 293 K. In the non-doped sample, the electron density distribution shows features characteristic at the copper atom in the Cu 2+ valence state and redistribution of the valence electrons of the Nd atom due to bonding. The substitution of Nd by Ce leads to a change in the valence state of Cu and changes the whole picture of the electron density.