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选用十二烷基苯磺酸钠(SDBS)作为表面活性剂,采用软液相合成法(soft-solution approach),通过控制表面活性剂十二烷基苯磺酸钠(SDBS)与FePt前驱体的摩尔比(SDBS/FePt),成功制备出了形貌各向异性的FePt纳米颗粒。XRD,TEM表征结果显示:调节摩尔比SDBS/FePt分别为7∶1,9∶1,11∶1时,所制备纳米颗粒均显示化学无序的面心立方(FCC)结构,但颗粒形貌却分别呈现出球形、不规则片状和树枝状结构。振动样品磁强计(VSM)检测结果显示:室温下,所制备颗粒矫顽力显示为零,均表现超顺磁性;惰性气体Ar保护下,500℃保温30 min热处理后,颗粒由超顺磁性转化为铁磁性;当调节摩尔比SDBS/FePt分别为7∶1,9∶1,11∶1时,矫顽力分别显示4489,30429,18457A.m-1;饱和磁化强度也大大改善,分别显示6.65,22.45,11.43 Am2.kg-1。由此可以看出:当调节摩尔比SDBS/FePt为9∶1时,磁能积相对最大。FePt纳米颗粒的磁性能是颗粒尺寸、形貌、组分、结晶性、结构等因素综合作用的结果,推测该结果主要与FePt纳米颗粒的各向异性形貌有关。通过改变表面活性剂的用量可以调节纳米颗粒的形貌,从而改善颗粒的磁性能,这为FePt纳米颗粒的形貌控制以及磁性能的调节提供了一条新途径。
Sodium dodecyl benzene sulfonate (SDBS) was chosen as the surfactant, and the soft-solution approach was used to control the surfactant activity of SDBS and FePt precursors (SDBS / FePt), successfully prepared morphologically anisotropic FePt nanoparticles. The results of XRD and TEM showed that all the prepared nanoparticles showed a chemical disordered face-centered cubic (FCC) structure when the molar ratio SDBS / FePt was 7:1, 9:1, 11:1 respectively, but the particle morphology But showed a spherical, irregular flake and dendritic structure. Vibrational sample magnetometer (VSM) test results show that: at room temperature, the coercivity of the prepared particles showed zero, all show superparamagnetism; under the protection of inert gas Ar, 500 ℃ for 30 min after heat treatment, the particles by the superparamagnetic When the molar ratio of SDBS / FePt is 7:1, 9:1, 11:1 respectively, the coercive force shows 4489,30429,18457A.m-1 respectively; the saturation magnetization also greatly improves, respectively Show 6.65, 22.45, 11.43 Am2.kg-1. It can be seen: when adjusting the molar ratio of SDBS / FePt 9: 1, the maximum energy product. The magnetic properties of FePt nanoparticles are the result of the combination of particle size, morphology, composition, crystallinity, structure and other factors. It is speculated that the results are mainly related to the anisotropic morphology of FePt nanoparticles. By changing the amount of surfactant can adjust the morphology of the nanoparticles to improve the magnetic properties of the particles, which provides a new way for the morphology control of FePt nanoparticles and the regulation of magnetic properties.