Influence of Nd-doping on the microstructure and electrical properties of Ca1-xNdxCeNbWO8+δ negative temperature coefficient ceramics

The effects of Nd-doping on the microstructure and electrical properties of Ca1-xNdxCeNbWO8+delta ceramics prepared by the traditional solid-state reaction route were investigated. XRD patterns reveal that all of the ceramics are assigned to the scheelite CaWO4 phase, whereas the cell volume of the ceramics decreases with the addition of Nd content. X-ray photoelectron spectroscopy (XPS) analysis confirms that the coexistence of Ce3+/Ce4+ ions, which is one of the fundamental reasons for the conductivity of Ca1-xNdxCeNbWO8+delta ceramics. The Ca1-xNdxCeNbWO8+delta ceramics show NTC behavior by observing a good linear relationship between the natural logarithm of resistivity (ln rho) and the reciprocal of the absolute temperature (1000/T) over a wide temperature range (0-600 degrees C). The values of electrical performance parameters rho(300), B-300/600 and E-a of the Ca1-xNdxCeNbWO8+delta compounds are in the range of 8710-15795 Omega cm, 5865.94-6383.89 K, 0.506-0.551 eV, respectively. With the increase of Nd doping, the resistivity, thermal constant B, and activation energy of the ceramics all decrease, indicating the electrical properties of the Ca1-xNdxCeNbWO8+delta compounds can be effectively adjusted by changing Nd3+ concentration.

Automated summary

The study found that Nd doping has a significant impact on the microstructure and electrical properties of Ca1-xNdxCeNbWO8+delta ceramics, and the electrical properties of the compounds can be effectively adjusted by changing the doping concentration.