Investigation of dielectric and electrical behaviour of rare-earth doped chlorapatites synthesized via hydrothermal method based on liquid solid solution

Abstract

In this paper the structural, dielectric and electrical conduction behaviour of Ca_6-xNa₂Y₂(SiO₄)₆(Cl)₂: xGd³⁺ (x = 0–0.05 mol%) chlorapatites prepared via hydrothermal process based on liquid–solid solution has been reported. The emergence of a monoclinic phase with P2₁/c space group is confirmed by x-ray diffraction (XRD) investigation. Space charge polarization is the predominant mechanism, according to dielectric studies that depend on frequency and temperature. Grain and grain boundary contributions to the thermally induced relaxation process are demonstrated using complex impedance spectroscopy. For all compositions, resistance of grain and grain boundaries exhibited negative temperature coefficient of resistance (NTCR) behaviour i.e., it decreases as temperature rises. The Nyquist plots indicated that the synthesized compounds appear non- Debye in nature. For all prepared compounds, the electrical modulus spectroscopy demonstrates that the electrical transport phenomenon occurs through both, short-range and long-range hopping of charge carriers. As frequency increases, the a. c. conductivity also increases, indicating that the compounds obey Jonscher’s power law.