矫顽力可调的多孔硅基Fe膜

采用电化学腐蚀法制备了不同多孔度的多孔硅(PS),再通过磁控溅射法在该PS衬底上沉积了一定厚度的Fe膜;并对样品进行了X射线衍射的结构分析、扫描隧道显微技术的表面形貌观察和磁光克尔效应的测量.发现在同一Fe膜厚度下，相对于参考样品硅上的Fe膜，多孔硅上Fe膜的矫顽力更大;同时观察到多孔硅基Fe膜随着PS多孔度的增加，矫顽力相应变大;而对于多孔度相同的多孔硅基样品,随着Fe膜厚度的增加矫顽力却逐步减小.得出了多孔硅特有的海绵状疏松结构能有效调节Fe膜矫顽力大小的结论. 关键词： 多孔硅 海绵状结构 Fe薄膜 矫顽力

Control of coercivity of iron films deposited on porous silicon substrates

Porous silicon (PS) with different porosity was obtained by anode electrochemical etching of boron-doped Si (100); the as-etched samples were then covered with Fe films by magnetron sputter technique. Analysis of surface profile and structural investigation were done by scanning tunneling microscopy and X-ray diffraction. Magneto-optical Kerr effect was employed to measure the hysteresis loops of the iron films sputtered onto PS and the reference sample on the Si substrate. The coercivity of the PS-based Fe films is larger than that of the Si-based ones, and increases with the porosity of the PS substrate. As for the PS-based samples with the same porosity, the coercivity of Fe films decreases with their thicknesses in a certain range. We found that the spongelike structure of PS can be effectively used to control the coercivity of iron films on the PS substrates.