?Synthesis, structural, optical and dielectric characterization of new pyrochlore solid solution B1.5Sb1.5Zn1-xCuxO700

A new pyrochlore solid solution with formula B1.5Sb1.5Zn1-xCuxO7 has been synthesized at high temperature with ceramic method at 1000 degrees C. A linear decrease of the cell parameter was observed according to the zinc con-centration decrease on B and A sites. Rietveld refinement of the compounds Bi1.5Sb1.5Zn1-xCuxO7 for x = 0, x = 0.5 and x = 1 by means of X-ray powder diffraction analysis confirmed an overall A2B2O7 cubic pyrochlore structure and Fd-3m symmetry. The reliability factors are respectively RBrag: 1.97; 4.31; 3.93 and Rf: 2.19; 4.15; 4.92. The UV-diffuse measurement shows absorbance evolution between UV and visible domain. Energy band gap calcu-lated by the Tauc method leads to values between 3.15 eV for the fraction x = 0 and 1.84eV for the fraction x = 1. A regular decrease is observed between the two values. Dielectric properties as a function of temperature show an increase in electrical conductivity with copper content.

Automated summary

A new pyrochlore solid solution B1.5Sb1.5Zn1-xCuxO7 has been synthesized at 1000 degrees C using ceramic method, showing a linear decrease in cell parameter with decreasing zinc concentration on B and A sites. Rietveld refinement confirmed its cubic pyrochlore structure and Fd-3m symmetry. The UV-diffuse measurement showed absorbance evolution between UV and visible domain, while the energy band gap calculated by the Tauc method decreased regularly from 3.15 eV to 1.84eV as the copper content increased. Dielectric properties revealed an increase in electrical conductivity with copper content.