The effect of post annealing treatment on the citrate sol–gel derived nanocrystalline BaFe₁₂O₁₉ powder: structural, morphological, optical and magnetic properties

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• 作者：B. C. Brightlin ; S. Balamurugan
• 关键词：Hexa ; ferrite ; BaFe12O19 ; Citrate sol–gel combustion ; Annealing ; Optical properties ; Morphology
• 刊名：Applied Nanoscience
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：6
• 期：8
• 页码：1199-1210
• 全文大小：2,337 KB
• 刊物类别：Chemistry and Materials Science
• 刊物主题：Materials Science
  Nanotechnology
  
• 出版者：Springer Berlin / Heidelberg
• ISSN：2190-5517
• 卷排序：6

文摘

The nanocrystalline BaFe₁₂O₁₉ powders were obtained from citrate sol–gel combustion-derived powder upon annealing at 800–1100 °C, and explored their structural, micro-structural, optical and magnetic properties. The thermal decomposition of citrate sol–gel combustion product was verified by means of thermogravimetric and differential thermal analysis. Structural identification of the citrate sol–gel combustion powder and annealed samples were investigated by powder X-ray diffraction. Though the combustion product exhibits cubic spinel phase material, the annealed powder yields good quality nanocrystalline hexagonal BaFe₁₂O₁₉ phase materials. The thin plate-like flakes morphology with random particle sizes of ~100–200 nm with slightly agglomerated particles of BaFe₁₂O₁₉ phase is analyzed by high resolution scanning electron microscopy for the good quality annealed sample. Photoluminescence emission spectrum of BaFe₁₂O₁₉ material reveals broad emission peak at ~360 nm under the excitation wavelength of 270 nm. Interestingly, the near infrared relative reflectivity of the nanocrystalline BaFe₁₂O₁₉ materials obtained by citrate sol-gel synthesis method is higher than the nanocrystalline BaFe₁₂O₁₉ materials obtained by mechano-thermal and co-precipitation method. The present dark brown colored BaFe₁₂O₁₉ materials can be applied as a ceramic color pigment which includes several applications. The room temperature magnetic hysteresis loop of the annealed BaFe₁₂O₁₉ sample exhibits a ferromagnetic saturation magnetization, M_s of 55.774 emu/g at 15 kOe.