Synthesis, Structural, Dielectric and Electrical Impedance Study of CaNb2O6 Phase Pure Materia

Abstract

Controlling the cooling rate during calcination pure columbite like phase of CaNb2O6 is synthesized. X-ray diffraction is used to identify
the phase. The phase is orthorhombic with lattice constants a=5.772A0 b=14.9897A0, c=5.2375A0 for the sample calcined at 12000C and sintered at 12500C. Density of material is 4.36 gm / cm3 (91.8% of theoretical density). Dielectric dispersion followed the Jonscher’s relation. Detailed analysis of impedance spectrum suggested that the electrical properties are strongly temperature dependent. AC impedance analysis results indicate that the relaxation mechanism of the material is temperature dependent and has dominant bulk contribution in different temperature ranges. The frequency dependent ac conductivity at different temperatures indicated that the
conduction is thermally activated process. AC conduction activation energies are estimated from Arrheneus plots and conduction mechanism is discussed.