Solid oxide materials were prepared via a solid state reaction route with a stoichiometry composition: x% of CaZrO3 and (100 - x)% of Gd2Zr2O7 (x = 10, 20, 33.3, 40). Powder X-ray diffraction under ambient and high-temperature ...

The effect of simultaneous substitutions of Ca at A site and Nb or Ta at B site in pyrochlore-type solid solutions: (CaxGd1-x)(2)(Zr1-xMx)(2) O-7 (x = 0.1, 0.2, 0.3, 0.4, 0.5 and M = Nb or Ta) were studied by powder X-ray ...

CaREZrNbO7 (RE=La, Nd, Sm, Gd and Y) system changed from fluorite (F)-type to pyrochlore (P)-type structure when the ionic radius ratios, r(Ca2+–RE3+)av/r(Zr4+–Nb5+)av were larger than 1.34. Thus, the La, Nd, and Sm ...

A new series of pyrochlore type ceramic semiconducting oxides in Ca–Ce–Ti–M–O (M = Nb or Ta) system has been synthesized by the conventional ceramic route. The electrical conductivity measurements show that these oxides ...

A series of quaternary nonstoichiometric cubic pyrochlores with varying cerium content in Ca-Ce-Ti-Nb-O system has been synthesized through solid state route. The powder X-ray diffraction and Rietveld analysis indicate ...