Structural and electrical properties of nonstoichiometric semiconducting pyrochlores in Ca-Ce-Ti-Nb-O system

► Nonstoichiometric semiconducting pyrochlores, CaCexTiNbO7−δ (x = 0.5-1.0) system have been synthesized by the conventional solid state route. ► CaCe0.7TiNbO6.55, crystallizes into a pure cubic pyrochlore structure by accommodating smaller Ti ions on the A site. ► The impedance analysis indicates relaxor behavior of these compounds due to disorder in the system.