Influence of dysprosium addition on the structural, morphological, electrical and magnetic properties of nano-crystalline W-type hexaferrites

Bulletin of materials science

Ali-Sharbati¹  R Mousarezaei¹  Javad-Mola Verdi Khani¹  G R Amiri¹ 

[1] Falavarjan Branch, Islamic Azad University, Isfahan 8315734317, Iran$$Falavarjan Branch, Islamic Azad University, Isfahan 8315734317, IranFalavarjan Branch, Islamic Azad University, Isfahan 8315734317, Iran$$

关键词: Nano-crystalline materials;    magnetic materials;    magnetic properties;    chemical synthesis.;   

DOI  :  

学科分类：材料工程

来源: Indian Academy of Sciences

【 摘 要 】

Dysporium (Dy)-substituted W-type barium hexaferrites were prepared by the citrate solâ€�?�gel-method. Crystalline structure, morphology, magnetic properties, DC resistivity and microwave absorption properties of BaNi₂Dy_ð‘�?Fe_{16−ð�?��?}O₂₇ (ð‘�? = 0-0.9) were studied using X-ray diffraction, transmission electron microscope (TEM), vibrating sample magnetometer and vector network analyzer and sensitive source meter, respectively. Single-phase W-type barium hexaferrites, with a chemical composition of BaNi₂Dy_ð‘�?Fe_{16−ð�?��?}O₂₇ (ð‘�? = 0-0.9), were formed by being heated at 1250°C for 4 h in air. The magnetic properties such as saturation magnetization (𝑀_s), and coercivity (𝐻_c) were calculated from hysteresis loops. Hysteresis loop measurements show that the coercivity values lie in the range of 530â€�??560 Oe with increasing Dy content. It was also observed that magnetization decreases with the increase of Dy content. The DC resistivity was observed to increase from 0.83 Ã�? 10⁷ to 6.92 Ã�? 10⁷ ð›�? cm with increasing Dy contents due to the unavailability of Fe³⁺ ions. Microwave absorption properties of hexaferrite (70 wt%)â€�?�acrylic resin (30 wt%) composites were measured by the standing-wave-ratio (SWR) method in the range from 12 to 20 GHz. For sample with ð‘�? = 0.6, a minimum reflection loss of âˆ�?40 dB was obtained at 16.2 GHz for a layer of 1.7 mm in thickness. Sample with ð‘�? = 0.9 had wide bandwidth absorption in the frequency range of 13.5â€�??18 GHz with reflection losses less than âˆ�?15 dB. Meanwhile the minimum reflection point shifts toward higher frequency with the increase of Dy content.

【 授权许可】

Unknown