Nonlinear electrical behaviors and conductivity mechanisms in Ca1‐xYbxCeNbWO8 ceramics

Abstract In this study, we investigated the nonlinear electrical behaviors and conductivity mechanisms of Ca 1‐ x Yb x CeNbWO 8 ceramics, which are prepared by the solid‐state sintering method. CeO 2 and CeNbO 4 phases occur when the Yb 3+ doping amount is greater than 0.1 in the CaCeNbWO 8 ‐based ceramics. With the continuous incorporation of Yb 3+ , the grain size of the ceramics first decreases and then increases. The Ce 3+ concentration in the ceramics decreases with increasing Yb 3+ content. In the temperature range of 298.15 to 1073.15K, the relationship between ln ρ and 1000/ T shows nonlinear electrical behaviors, which is attributed to the different conductivity mechanisms at high and low temperatures ( ρ and T are resistivity and temperature, respectively). In the temperature range of 298.15 to 773.15K, the electrical conduction in Ca 1‐ x Yb x CeNbWO 8 ceramics follows the Efros‐Shklovskii variable‐range hopping (ES‐VRH) conduction mechanism, thermal activation conduction ( x < 0.2), and two‐dimensional Mott VRH conduction mechanism ( x = 0.2). Furthermore, the electrical conduction obeys the thermal activation conduction mechanism in the temperature range of 773.15 to 1073.15K. The activation energy for the electrical conduction is calculated based on the different hopping conduction mechanisms.