Impedance study of spark–plasma–sintered lutetium titanate ceramics: Effect of post–annealing

Fabrication and electrical conductivity of Lu2(Ti1-xHfx)2O7 transparent ceramics prepared by spark plasma sintering

“…Figure 8 shows the Nyquist impedance plots of Lu 2 (Ti 1-x Hf x ) 2 O 7 (x = 0-0.5) transparent ceramics at 823 K. The impedance decreases and then increased with increasing x, which can be clearly seen in Figure 8 (b). Two unresolved semicircles with a spike were observed and were fitted using the equivalent circuit with a series of three parallel R and a CPE in x = 0 [13].…”

“…In this study, a relatively high activation energy (1.26 eV) and low bulk conductivity was obtained in Lu 2 Ti 2 O 7 (x = 0) transparent ceramic compared to the literature. This might be due to the different preparation process and transparent ceramics with high density and high purity [13]. Pirzada et al [25] predicted that the A 2 B 2 O 7 compounds with B 4+ cation radii of larger or intermediate size (i.e.…”