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RESEARCH PRODUCT
Dielectric relaxation and polaronic hopping in Mn-substituted LaSrNiO4 nickelates prepared by mechanical milling method
A. ChouketMohamed KhitouniO. BidaultA. CheikhrouhouW. Cheikhrouhou-koubaaVirgil Optasanusubject
Materials scienceRietveld refinementScanning electron microscopeMechanical EngineeringMetals and AlloysAnalytical chemistry02 engineering and technologyActivation energyDielectric021001 nanoscience & nanotechnologyMicrostructure01 natural sciencesIonCrystallographyTetragonal crystal systemMechanics of Materialsvisual_art0103 physical sciencesMaterials Chemistryvisual_art.visual_art_mediumCeramic010306 general physics0210 nano-technologydescription
Abstract The structures, microstructures and dielectric properties of LaSrNi1−xMnxO4 (x = 0, 0.1, 0.2, 0.3 and 0.5) ceramics synthetized by mechanical milling followed by heat treatment were studied. One single tetragonal phase was revealed in all compounds. Structural parameters were obtained by Rietveld refinement. The substitution of Ni ions by Mn produces a variation of the lattice parameters but no phase change is observed. The surface morphology and elemental analysis of these samples were respectively investigated by Scanning Electron Microscopy (SEM) and energy dispersive X-ray technique (EDS). Giant dielectric response was observed in these ceramics, and at least two relaxations were found on the curve of the temperature dependence of dielectric constant. An equivalent circuit [R-C][R-CPE] was used to fit the experimental data and provide the activation energy of the thermally activated relaxation. The activation energy values confirm the thermally activated small polaronic hopping contribution to the giant dielectric response.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2016-12-01 | Journal of Alloys and Compounds |