Dielectric Properties of Cr3+ Doped Al2O3 of a Hierarchical Nanostructure Synthesized Using a Highly Porous Precursor of Tubular AlO(OH)⋅αH2O Fibers
| Autor: | Amit Kumar Sudhansu, Shanker Ram, Surendra Jangu, Sanjeev Kumar Sharma |
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| Rok vydání: | 2021 |
| Předmět: |
Materials science
Nanostructure Mechanical Engineering Doping Dielectric permittivity Solid-state 02 engineering and technology Dielectric 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Chemical engineering Mechanics of Materials Highly porous General Materials Science 0210 nano-technology |
| Zdroj: | Materials Science Forum. 1019:135-141 |
| ISSN: | 1662-9752 |
| Popis: | Herein, we have developed a Cr3+ doped Al2O3 of a hierarchical nanostructure by a simple two-step synthesis. A pure AlO(OH)⋅αH2O, as synthesized in forms of small tubular fibers by hydrolysis of Al-metal sheets, is easily doped with selective Cr3+ dosages up to 2.0 mol% using an aqueous CrO3. As-synthesized samples exhibit XRD of a single phase Cr3+: Al2O3 of a rhombohedral crystal structure. Average pore-volume is decreased as 98.1, 89.8, and 61.5 cm3-g-1 in the 0.5, 1.0 and 2.0 % Cr% doped samples, with average pore radius of 1.70, 2.17 and 1.90 nm, respectively, as measure from BET specific surface area. Local Al-O vibrations exhibit IR bands of 400 to 1200 cm-1 intrinsic of oxygen polygons. At room temperature, a duly tailored dielectric permittivity of 480 is obtained in a 2.0 mol% Cr3+:Al2O3 and that is enhanced progressively on heating it over 25 to 300 °C, showing a value 6700 at 300 °C in phonon induced dynamics of charge carriers, useful for solid-state electronics. |
| Databáze: | OpenAIRE |
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