利用PS模板制备多孔SrFe12O19薄膜的研究

Study of Porous SrFe12O19 Thin Films Using PS Template Assistant

摘要:

本文以提拉浸渍法使用聚苯乙烯(PS)球模板制备了有序多孔结构的锶铁氧体(SrFe12O19)薄膜。将微乳液聚合法合成的PS球,通过提拉浸渍法有序地组装在硅片基板上形成PS模板；使用溶胶-凝胶法制备SrFe12O19前驱体溶胶,再采用提拉浸渍法使SrFe12O19前驱体溶胶填充PS模板的空隙,在900 ℃保温2 h去除PS球后即制得多孔SrFe12O19薄膜。重点研究了聚乙烯吡咯烷酮(PVP)的含量对PS球微观形貌,浸渍时间对PS模板以及多孔SrFe12O19薄膜微观形貌的影响,并对多孔SrFe12O19薄膜的形成机理进行了讨论,建立了相应的模型。结果表明：添加0.2 g的PVP可得到粒径均匀的PS球,且微球之间空隙明显；将硅片在PS球乳液中浸渍10 s可得到单层有序的PS模板；当PS模板在SrFe12O19前驱体溶胶中浸渍10 s时可制备出孔径约200 nm的蜂窝状多孔结构的纯SrFe12O19相薄膜,其表现出优异的硬磁性能：饱和磁化强度为27.9 emu/g,剩磁为15.5 emu/g,矫顽力为2613.4 Oe。

Abstract:

In this paper, ordered porous strontium ferrite (SrFe12O19) thin films were prepared by dip-drawing method using polystyrene (PS) spheres template. The PS template was orderly assembled on clean silicon substrate through PS sphere emulsion, which was synthesized by microemulsion polymerization. The porous SrFe12O19 thin films were fabricated by filling the SrFe12O19 precursor sol prepared by sol-gel method on the interspaces among adjacent PS spheres in the PS template, and then removing the PS spheres by heating at 900 °C for 2 h. The effects of PVP content on the microstructure of PS spheres and the drawing time on the microstructure of PS template and the porous SrFe12O19 thin films were investigated. Then the formation mechanism of porous SrFe12O19 thin films was discussed, and the corresponding model was established. The results show that PS spheres with uniform particle size could be obtained by adding 0.2 g PVP, and the interspaces between the microspheres were obvious; the single layer ordered PS template could be obtained by immersing the silicon substrate in the PS sphere emulsion for 10 s. The pure SrFe12O19 porous thin film with honeycomb structure and a pore diameter of about 200 nm can be prepared by immersing PS template in the SrFe12O19 precursor sol for 10 s, and it shows the excellent hard magnetic properties: saturation magnetization of 27.9 emu/g, remanence of 15.5 emu/g and coercivity of 2613.4 Oe.