Electrical Conduction Mechanisms in Rare Earth-doped WO₃ Ceramics: Experimental and Theoretical Approaches

This study has been carried out to investigate the effect of dopant on the structural, and electrical properties of tungsten trioxide nanoparticles. W_1-xGd_xO₃ nanoparticles (x = 0, 0.02, 0.05, and 0.10) were fabricated via a co-precipitation route. The detailed study of frequency-dependent dielectric and electrical properties were studied in the temperature range 303 K - 473 K. A notable shift from nearly constant loss (NCL) to Super Linear-Power Law (SPL) behavior at 373 K is observed, further validated by the dielectric loss spectra. The trends in the frequency exponent indicate that the mechanism of charge transfer follows the quantum mechanical tunneling (QMT) and non-overlapping small polaron tunneling (NSPT) model. Furthermore, the electrical properties were elucidated by impedance spectroscopy which shows the non-Debye type relaxation process.