Open AccessDielectric relaxation and conduction mechanism of NaMgPO4 compound
Author(s) -
L. Miladi,
A. Oueslati,
M. Ben Gzaiel,
M. Gargouri
Publication year - 2022
Publication title -
journal of advanced dielectrics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.38
H-Index - 13
eISSN - 2010-135X
pISSN - 2010-1368
DOI - 10.1142/s2010135x21500326
Subject(s) - materials science , raman spectroscopy , grain boundary , temperature coefficient , dielectric , arrhenius equation , relaxation (psychology) , dielectric spectroscopy , analytical chemistry (journal) , crystallite , activation energy , conductivity , condensed matter physics , phase transition , crystallography , microstructure , chemistry , physics , optics , psychology , social psychology , optoelectronics , electrode , electrochemistry , chromatography , metallurgy , composite material
The polycrystalline NaMgPO 4 ceramic, synthesized via a high-temperature solid-state reaction route, has been characterized by using different experimental procedures. The X-ray powder diffraction confirmed the phase formation of the synthesized compound in the orthorhombic phase. It assumed an olivine-type structure made up of corners linked between tetrahedral PO 4 and octahedral NaO 6 and MgO 6 groups. Infrared and Raman spectroscopies confirmed the presence of PO[Formula: see text] groups. Local structure and chemical bonding between MgO 6 octahedral and PO[Formula: see text] tetrahedral groups investigated by diffusion Raman is the feature in the phase transition at [Formula: see text] 693 K. The temperature dependences of the real [Formula: see text] and imaginary [Formula: see text] parts of dielectric permittivity show a distribution of relaxation times. From Nyquist plots, the presence of grain and grain boundary effect in the material is noticed. The impedance spectroscopy measurement showed a non-Debye-type process. From the impedance data, the determined grain resistance reduces with increment of temperature showing negative temperature coefficient of resistance (NTCR)-type nature of the material which also confirmed from conductivity analysis. The temperature dependence of [Formula: see text] reveals an Arrhenius-type behavior with two activation energies, 0.98 eV in region I and 0.67 eV in region II. Studied sample’s conduction is assured by Na[Formula: see text] ions’ hopping in tunnels and its mechanism was discussed.