反相微乳液助水热法可控合成FeNi3合金纳米结构

Controlled Syntheses of FeNi_3 Alloy Nanostructures via Reverse Microemulsion-Directed Hydrothermal Motheds

利用水热法处理表面活性剂/正辛烷/正己醇/水四元微乳体系成功合成FeNi3合金纳米结构.通过改变表面活性剂的用量和类型来调控产物粒径与形貌.当表面活性剂为聚乙二醇4000(PEG4000)时,产物为球状,粒径约为75nm.当表面活性剂为十六烷基三甲基溴化铵(CTAB)时,产物为海胆状.单个海胆状颗粒是由许多纳米棒构成,其直径约为42nm,长度为0.4-1.2μm.利用X射线粉末衍射(XRD),穆斯堡尔谱,扫描电子显微镜(SEM),透射电子显微镜(TEM),选区电子衍射(SAED),多功能磁天平(MMVFTB)等测试手段对产物的组成、形貌和磁性能进行了表征.球状和海胆状的FeNi3样品在室温下呈现典型的铁磁性特征,其饱和磁化强度(Ms)值分别为114.4和97.4emu·g-1,矫顽力(Hc)值分别为94.0和329.0Oe.

FeNia alloy nanostmctures were synthesized by bydrothermal methods in the -hexanol/ water quaternary reverse microemulsion systems. The size and shape of the products could be controlled by changing the type and dosage of the surfactant. Spherical particles with a diameter of ca 75 nm were prepared when polyethylene glycol 4000 （PEG4000） was used as the surfactant. Sea-urchin-like particle was obtained when cetyltrimethylammonium bromide （CTAB） was used as the surfactant. The single sea-urchin-like particles were composed of many nanorods with diameters of ca 42 nm and lengths of 0.4-1.2 μm. The as-synthesized products were characterized by powder X-ray diffraction （XRD）, Moessbaner spectroscopy, scanning electronic microscopy （SEM）, transmission electron microscopy （TEM）, selected area electron diffraction （SAED）, and multi-purpose magnetic variable field translation balance （MM VFrB）. Both the spherical and sea-urchin-like FeNi3 samples exhibited typical ferromagnetic behavior at room temperature. Their saturation magnetization values （Ms） were 114.4 and 97.4 emu· g^-1, respectively, while their coercivity values （He） were 94.0 and 329.0 0e, respectively.