Structural characterization of (Bi1-xGdx)14W2O27 (x = 0.00 and 0.05) synthesized via mechano-thermal treatment

Structural characterization of (Bi1-xGdx)14W2O27 (x = 0.00 and 0.05) synthesized via mechano-thermal treatment

R. T. Santiago and D. S. Vieira and R. L. Biagio and V. G. Camargo and C. F. C. Machado and M. Fabián and K. L. da Silva and V. Šepelák, Integrated Ferroelectrics 174, 56-62 (2016). PDF | DOI

Samples of (Bi1-xGdx)14W2O27 (x = 0 and 0.05) compounds were prepared via a combination of mechanochemical and thermal treatments upon a Bi2O3/WO3/Gd2O3 stoichiometric mixture of precursors. Phase evolution, as well as the determination of structural parameters in as-prepared compounds, were performed by XRD analysis. Rietveld refinement revealed that gadolinium ions are incorporated into the tetragonal structure of Bi14W2O27 with preference to occupy octahedrally coordinated Bi3+ sites. The Gd doping induced an increase in Bi sites coordination, i.e., the number of oxygens around Bi/Gd ions increased, which can be explained by the absence of 6s2 lone pair electrons in gadolinium ions.