High-Density Single-Phase Yttrium-Gadolinum-Iron Garnets by Spray Drying
| Autor: | F.R. Lamastra, Federica Leonardi, Francesca Nanni, Gualtiero Gusmano, Alessandra Bianco |
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| Rok vydání: | 2008 |
| Předmět: |
Marketing
Materials science Metallurgy chemistry.chemical_element Sulfuric acid Yttrium Condensed Matter Physics Microstructure law.invention Thermogravimetry chemistry.chemical_compound chemistry Chemical engineering law Spray drying visual_art Differential thermal analysis Materials Chemistry Ceramics and Composites visual_art.visual_art_medium Calcination Ceramic |
| Zdroj: | International Journal of Applied Ceramic Technology. 5:624-632 |
| ISSN: | 1744-7402 1546-542X |
| DOI: | 10.1111/j.1744-7402.2008.02239.x |
| Popis: | Yttrium–iron garnet (YIG)-based ceramics are largely used in microwave devices, sensors, lasers, phosphorescent sources, and magneto–optical applications. In this research, high-density, single-phase Gd(0.4)-YIG were obtained by spray drying starting from nonstoichiometric, iron-rich, metal nitrate solutions. Aqueous metal nitrate solutions, containing polyvinyl alcohol (PVA) and polyethylene glycol (PEG), were prepared and sprayed to obtain precursor powders. In some cases either sulfuric acid or hydrochloric acid were added to the initial solution. On the basis of differential thermal analysis and thermogravimetry analysis, as-sprayed powders were calcined between 600°C and 1200°C and then characterized by induced coupled plasma spectroscopy, X-ray diffraction, and high-temperature X-ray diffraction. According to thermal dilatometry results, powders calcined at 1200°C were sintered in air up to 1470°C. The microstructure of sintered ceramics was made up of fine grains, being an average size of about 10 μm. It was found that addition of an inorganic acid to the precursor solution is essential to obtain high-density (98%) sintered materials. Ferromagnetic resonance linewidth (ΔH−3 dB) measurements on sintered materials were also performed. |
| Databáze: | OpenAIRE |
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