Release time:2021-03-15 Hits:
- Key Words:Scanning electron microscopy;Enamels - Field emission microscopes - Hematite - Magnetic materials - Magnetite - Nanostructures - Photoelectron spectroscopy - Sodium Borohydride
- Abstract:Rational design on microstructure of magnetic material provides new opportunity to enhance the electromagnetic absorption performance. Herein, we demonstrate the successful preparation of spindle-cone of Fe/Fe<inf>2</inf>O<inf>3</inf> and Fe<inf>3</inf>O<inf>4</inf> samples with an average size of ∼1.2 μm, using a facile two-steps method. The well-defined spindle-cone shaped α-Fe<inf>2</inf>O<inf>3</inf> was developed first by a solvothermal route and then reduced by H<inf>2</inf> or NaBH<inf>4</inf>, respectively. The morphologies, phase compositions and magnetization of these as-prepared samples are analyzed by Field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD) and X-ray photoelectron spectrum (XPS) and vibrating sample magnetometer (VSM). Meanwhile, the electromagnetic (EM) absorption performance of Fe/Fe<inf>2</inf>O<inf>3</inf> and Fe<inf>3</inf>O<inf>4</inf> spindle-cones-paraffin composites with various filling ratios are also studied. The results reveal that Fe/Fe<inf>2</inf>O<inf>3</inf> with a filling ratio of 50 wt% achieves the smallest reflection loss value of −26.2 dB at a thickness of 1.4 mm. At thinner thickness (1.0 mm), the bandwidth (RL < −10 dB) equals to 4.5 GHz (13.5–18 GHz). The excellent absorption mechanism was discussed in this work, which attributed to the unique nanostructure and moderate impedance matching and EM loss ability.<br/> © 2019 Elsevier B.V.
- Volume:799
- Translation or Not:no
