STABILITY AND ANTIPHASE DOMAIN-STRUCTURE OF THE PYROCHLORE SOLID-SOLUTION IN THE ZRO2-GD2O3 SYSTEM

The stability of the pyrochlore-type solid solution in the system (1-x)ZrO//2-xGdO//1//. //5 has been studied by means of X-ray diffraction. The powder samples were synthesized by wet-chemical method. The X-ray diffraction study shows that the pyrochlore-type solid solution is stable within the compositional range of 0. 33 less than equivalent to x less than equivalent to 0. 60 at 1500 degree C, which is consistent with composition dependence of lattice constant and physical parameters in conductivity. Broad superstructure peaks of the pyrochlore-type have been observed in the X-ray powder diffraction for the samples within the compositional ranges 0. 33 x multiplied by less than equivalent to 0. 43 and 0. 57 less than equivalent to x less than equivalent to 0. 62 sintered at 1500 degree C, and 0. 46 x multiplied by less than equivalent to 0. 54 annealed at 1600 degree C.