Ionic conductivity and dielectric relaxation studies of a low-temperature form of silver zinc phosphate

• Published in: Journal of alloys and compounds Vol. 747; pp. 543 - 549
• Main Authors: Chakchouk, Narimen, Louati, Bassem, Guidara, Kamel
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 30.05.2018; Elsevier BV
• Subjects: Conduction heating; Conduction mechanism; Conductivity; Dielectric properties; Dielectric relaxation; Dielectrics; Electrical resistivity; Heat measurement; Ion currents; Low temperature; Phase transition; Phase transitions; Polycrystals; Solid state physics; Vibration mode; X-ray diffraction; Zinc phosphate; α-AgZnPO4; X-ray diffraction; Conduction mechanism; α-AgZnPO4; Dielectric properties; Phase transition
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.03.036

Polycrystalline α-AgZnPO4 was prepared by the conventional solid-state reaction method. X-ray diffraction analysis at room temperature indicated the formation of a single phase hexagonal structure (space group P63). It crystallizes with a structure similar to those of high-temperature NaCoPO4 and KZnPO4. Besides, all vibration modes of tetrahedral PO4 appeared in the Raman spectrum. Two phase transitions at (438, 462) K were obtained by means of Differential scanning calorimetry (DSC). Furthermore, the electrical conductivity and the dielectric properties of this material were analyzed by means of the impedance spectroscopy technique, in a frequency ranging from 209 Hz to 1 MHz and temperature range (395–526) K. The phase transition observed in the calorimetric study was confirmed by the σdc and fpvariation as a function of temperature. The conduction mechanism was interpreted by the CBH model in phase I and II and by the NSPT model in the phase III. •Ac conductivity data affirm that for high frequencies σac is proportional to ωs.•The phase transition observed in the calorimetric study was confirmed by the σdc as a function of temperature.•The conduction mechanism was interpreted by the CBH model in phase I and II and by the NSPT model in the phase III.