Influence of Zn 2+ ions on the structural and electrical properties of Mg 1−x Zn x FeCrO 4 spinels
| Autor: | Abbasher M. Gismelseed, Hisham M. Widatallah, A.H. Al-Rajhi, Musa S. Shongwe, Mohd. Hashim, K.O. Al-Riyami, K. S. Al-Rashdi, S.K. Jameel, Kadhim A.M. Khalaf, Azzouz Sellai, Abdulhakim Al-Rawas, Majid S. Al-Ruqeishi |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Materials science Scanning electron microscope Mechanical Engineering Metals and Alloys Analytical chemistry 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Lattice constant Mechanics of Materials Transmission electron microscopy Electrical resistivity and conductivity Vacancy defect Differential thermal analysis 0103 physical sciences Materials Chemistry Ferrite (magnet) Crystallite 0210 nano-technology |
| Zdroj: | Journal of Alloys and Compounds. 657:733-747 |
| ISSN: | 0925-8388 |
| Popis: | The polycrystalline magnesium–zinc ferrite chromate having the chemical formula Mg 1−x Zn x FeCrO 4 (0.0 ≤ x ≤ 1.0) were prepared by conventional solid phase reaction using high purity reagents. The structural and electrical properties at room temperature have been investigated by XRD, TEM, SEM, EDS, TGA, DTA, FT-IR and DC electrical resistivity techniques. The lattice parameters such as the lattice constant, average particle size, bonds length, density, porosity and volume shrinkage were found to vary with increasing Zn 2+ content in the sample. The lattice constant “a” increases from 8.361 A for MgFeCrO 4 to 8.382 A for ZnFeCrO 4 spinels. The IR spectra confirm the presence of two main absorption bands υ 1 and υ 2 in the frequency range of 400–1000 cm −1 , arising due to the tetrahedral (A) and octahedral (B) stretching vibrations respectively. Values of υ 1 and υ 2 decrease with increasing Zn +2 content over the whole composition range. The scanning electron microscope (SEM) and transmission electron microscope (TEM) micrographs showed aggregates of stacked large grains. Values of the room temperature DC electrical resistivity decrease as Zn 2+ content increases. The low values of the vacancy model parameters indicate that the Mg 1−x Zn x FeCrO 4 spinels are strongly defective and the participation of the Zn 2+ vacancies in the improvement of the electrical conductivity in these spinels. The thermo-gravimetric, TGA and differential thermal analysis, DTA show loss of mass caused by vaporization of the surface and trapped water molecules at higher temperatures. |
| Databáze: | OpenAIRE |
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