Granitzer Petra, Rumpf Klemens, Ohta Toshiyuki, Koshida Nobuyoshi, Poelt Peter, Reissner Michael
Institute of Physics, Karl Franzens University Graz, Universitaetsplatz 5, Graz, A-8010, Austria.
Nanoscale Res Lett. 2012 Jul 11;7(1):384. doi: 10.1186/1556-276X-7-384.
Ferromagnetic nanostructures have been electrodeposited within the pores of porous silicon templates with average pore diameters between 25 and 60 nm. In this diameter regime, the pore formation in general is accompanied by dendritic growth resulting in rough pore walls, which involves metal deposits also offering a branched structure. These side branches influence the magnetic properties of the composite system not only due to modified and peculiar stray fields but also because of a reduced interpore spacing by the approaching of adjacent side pores. To improve the morphology of the porous silicon structures, a magnetic field up to 8 T has been applied during the formation process. The magnetic field etching results in smaller pore diameters with less dendritic side pores. Deposition of a ferromagnetic metal within these templates leads to less branched nanostructures and, thus, to an enhancement of the coercivity of the system and also to a significantly increased magnetic anisotropy. So magnetic field-assisted etching is an appropriate tool to improve the structure of the template concerning the decrease of the dendritic pore growth and to advance the magnetic properties of the composite material.
铁磁纳米结构已被电沉积在平均孔径为25至60纳米的多孔硅模板的孔内。在这个直径范围内，孔的形成通常伴随着枝晶生长，导致孔壁粗糙，这也使得金属沉积物呈现出分支结构。这些侧枝不仅由于修正和特殊的杂散场，而且由于相邻侧孔的靠近导致孔间距减小，从而影响复合系统的磁性。为了改善多孔硅结构的形态，在形成过程中施加了高达8T的磁场。磁场蚀刻导致孔径更小，枝状侧孔更少。在这些模板内沉积铁磁金属会导致纳米结构的分支减少，从而提高系统的矫顽力，并显著增加磁各向异性。因此，磁场辅助蚀刻是一种合适的工具，可用于改善模板结构，减少枝状孔生长，并提高复合材料的磁性。
