Magnetic properties of structurally confined FePt nanoparticles within mesoporous nanotubes
Magnetic properties of structurally confined FePt nanoparticles within mesoporous nanotubes
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DOI：
10.1016/j.jmmm.2006.11.180
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发表时间：
2007-03
影响因子：
2.7
通讯作者：
Jin-Seung Jung;J. Lim;L. Malkinski;A. Vovk;K. Choi;S.-L. Oh;Yong Rok Kim;J. Jun
中科院分区：
文献类型：
--
作者：
Jin-Seung Jung;J. Lim;L. Malkinski;A. Vovk;K. Choi;S.-L. Oh;Yong Rok Kim;J. Jun
Chemically ordered FePt binary alloys with L10face-centered tetragonal (fct) structure have recently attracted considerable attention due to their excellent intrinsic magnetic chemical and mechanical properties. In particular, one-dimensional (1-D) arrays of FePt alloys are prospective materials for ultrahigh density magnetic storage media. We describe a new method to fabricate FePt alloy nanostructures embedded in the nanochannels of anodic alumina templates (AAT) and SBA15 silica through infiltrating porous membranes with FePt nanoparticles. SBA15 silica nanotube is a honeycomb structure with tubular channels of 9nm in diameter, extending through 10μm long particles. In contrast AAT have morphology of a membrane with regular array of pores 60nm in diameter. To transform the FePt alloy phase from chemically disordered face-centered-cubic to chemically ordered L10phase the membrane was annealed at 700∘C in a H2–N2gas mixture for 2h. Transmission electron microscope (TEM) and field emission scanning electron microscope (FESEM) show that nanoparticles transformed into isolated superparamagnetic nanoparticles in SBA15 and elongated nanostructure in AAT due to the annealing treatment. The magnetization was measured by quantum interference device (SQUID). The ordered fct FePt polycrystalline nanostructure in AAT have high magnetic anisotropy and thus large coercivity up to 1.1T at room temperature.
