• Journal of Advanced Dielectrics
  • Vol. 12, Issue 3, 2150032 (2022)
L. Miladi*, A. Oueslati*, M. Ben Gzaiel*, and M. Gargouri*
Author Affiliations
  • Laboratory of Spectroscopic Characterization and Optical Materials, Faculty of Sciences, University of Sfax B.P. 1171, 3000 Sfax, Tunisia
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    DOI: 10.1142/S2010135X21500326 Cite this Article
    L. Miladi, A. Oueslati, M. Ben Gzaiel, M. Gargouri. Dielectric relaxation and conduction mechanism of NaMgPO4 compound[J]. Journal of Advanced Dielectrics, 2022, 12(3): 2150032 Copy Citation Text show less

    Abstract

    The polycrystalline NaMgPO4 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 PO4 and octahedral NaO6 and MgO6 groups. Infrared and Raman spectroscopies confirmed the presence of PO43 groups. Local structure and chemical bonding between MgO6 octahedral and PO43 tetrahedral groups investigated by diffusion Raman is the feature in the phase transition at T= 693 K. The temperature dependences of the real 𝜀 and imaginary 𝜀 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 σdc 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+ ions’ hopping in tunnels and its mechanism was discussed.The polycrystalline NaMgPO4 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 PO4 and octahedral NaO6 and MgO6 groups. Infrared and Raman spectroscopies confirmed the presence of PO43 groups. Local structure and chemical bonding between MgO6 octahedral and PO43 tetrahedral groups investigated by diffusion Raman is the feature in the phase transition at T= 693 K. The temperature dependences of the real 𝜀 and imaginary 𝜀 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 σdc 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+ ions’ hopping in tunnels and its mechanism was discussed.
    L. Miladi, A. Oueslati, M. Ben Gzaiel, M. Gargouri. Dielectric relaxation and conduction mechanism of NaMgPO4 compound[J]. Journal of Advanced Dielectrics, 2022, 12(3): 2150032
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