The preparation and characterization of polymer-derived Fe/Si/C magnetoceramics

详细信息    查看全文

• 作者：Yanzi Gou ; ^{y.gou2012@hotmail.com" class="auth_mail" title="E-mail the corresponding author} ; Xuan Tong ; Qiance Zhang ; Bing Wang ; Qi Shi ; Hao Wang ; Zhengfang Xie ; Yingde Wang
• 关键词：Fe/Si/C ; Ceramics ; Magnetic ; Precursor ; Polymer-derived
• 刊名：Ceramics International
• 出版年：2016
• 出版时间：January 2016
• 年：2016
• 卷：42
• 期：1
• 页码：681-689
• 全文大小：1844 K

文摘

In this work, the preparation of polymer-derived Fe/Si/C ceramics was achieved by synthesis and pyrolysis of the preceramic hyperbranched polyferrocenylsilane. The Fe/Si/C ceramics obtained under various experimental conditions such as different pyrolytic temperatures, atmospheres and heating rates, were investigated by TG–MS, XRD, and XPS. Moreover, the magnetic properties of the ceramics were investigated by the vibrating sample magnetometer (VSM). Experimental results indicated that the pyrolysis of the preceramic polymer started above 250 °C and completed among 800–1000 °C. The crystallization of the pyrolytic product started at 500 °C. Besides the heat treatment temperature, the atmosphere and heating rate also played important roles in the composition and magnetic properties of the corresponding Fe/Si/C ceramics. Fe existed as α-Fe in ceramics sintered at 900 °C under N₂ and NH₃ atmospheres. However, the main components in ceramic product sintered under air were γ-Fe₂O₃ and carbon. Although all of the three ceramic products sintered under different atmosphere were ferromagnetic with low remanent magnetization and coercivity, the ceramics sintered under NH₃ had the largest saturation magnetization. The saturation magnetization of the Fe/Si/C ceramics further ascended when fabricated under NH₃ with a slower heating rate, in which Fe existed as α-Fe, Fe₃O₄ and γ′-Fe₄N.