Rietveld refinement and electron density distribution in CuxV2O5

TL;DR

This study investigates how copper doping affects the crystal structure and electron distribution in CuxV2O5 using X-ray diffraction and maximum entropy methods, revealing charge transfer and disorder effects.

Contribution

It provides detailed structural and electron density analysis of CuxV2O5 with varying copper content, highlighting charge transfer mechanisms and disorder phenomena.

Findings

Copper addition causes positional and charge disorder in V-O network.

Electrons from copper are transferred to specific vanadium sites.

Structural parameters vary systematically with copper content.

Abstract

Room temperature powder x-ray diffraction measurements have been carried out on polycrystalline samples of CuxV2O5 with x = 0.33, 0.40, 0.50, 0.55 and 0.60, prepared by solid state reaction in evacuated quartz tubes. All the samples were found to be in single-phase monoclinic structure. Rietveld full profile refinement of the x-ray diffraction data yielded the lattice parameters and fractional atom coordinates. Maximum entropy inversion of the diffraction data was done in order to obtain the variation in the spatial electron density distribution as a function of copper composition. These density maps show progressive positional and charge disorders in the V-O network induced by addition of copper. It is shown that the electrons donated by copper atoms are transferred to the specific vanadium atom sites.