Structural, vibrational spectroscopic, and electrical conduction mechanisms of α-NaCoPO4 compound
Autor: | A. Ben Rhaiem, M. Chemingui, Frédéric Boschini, Abdelfattah Mahmoud, A. Ajmi |
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Rok vydání: | 2019 |
Předmět: |
Diffraction
Phase transition Materials science Infrared General Chemical Engineering General Engineering Analytical chemistry General Physics and Astronomy 02 engineering and technology Conductivity 010402 general chemistry 021001 nanoscience & nanotechnology Polaron 01 natural sciences 0104 chemical sciences symbols.namesake symbols General Materials Science Orthorhombic crystal system 0210 nano-technology Thermal analysis Raman spectroscopy |
Zdroj: | Ionics. 25:1091-1103 |
ISSN: | 1862-0760 0947-7047 |
DOI: | 10.1007/s11581-019-02851-7 |
Popis: | The orthophosphate α-NaCoPO4 compound was prepared from highly pure constituents with mechanical milling followed by heat treatment. X-ray diffraction data refined via Rietveld method revealed that this compound crystallizes in the orthorhombic system with Pnma space group. A thermal analysis shows that this composition undergoes one-phase transitions at T = 567 K. The infrared and Raman spectra confirm the presence of PO43− tetrahedral. The evolution of half-width Δν and intensity report versus temperature introduces huge changes associated with the phase transition originating from the reorientation of the PO4 tetrahedra. Besides, the electrical data analysis of the impedance spectra is adapted to an equivalent circuit. Furthermore, the alternating current (AC) conductivity of grain contribution is interpreted using the Jonscher’s universal power law. The AC conductivity behavior is ensured by a single process defined as a hopping transport mechanism. The conductivity frequency dependence is interpreted using the non-overlapping small polaron tunneling model (NSPT) in the two phases. |
Databáze: | OpenAIRE |
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