【作者】 杜春岭；

【导师】 杜雪岩；

【作者基本信息】 兰州理工大学 ， 材料学， 2010， 硕士

【摘要】 本文分别以硫酸亚铁(FeSO4·7H2O)、氯铂酸(H2PtCl6·6H2O)作为铁源和铂源,采用多脉冲电沉积法在水溶液中分别制备了FePtx磁性纳米颗粒与薄膜。利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、扫描电镜(SEM)和振动样品磁强计(VSM)对热处理前后的FePtx磁性纳米颗粒与薄膜的物相、形貌和磁性能进行了表征。主要研究内容如下：1)X射线衍射(XRD)分析表明制得的FePtx磁性纳米颗粒是FCC结构的(Fe, Pt)固溶体,在N2气氛下经过700℃、30min的热处理后转变为L12结构；配备有能谱分析仪(EDX)的透射电子显微镜(TEM)分析表明制得的FePtx磁性纳米颗粒平均粒径在2.5nm左右。采用震动样品磁强计(VSM)测试热处理前后的FePtx的磁性能,由于热处理后的FePtx颗粒部分是L10结构,其矫顽力由零增加到150.00Oe。此外,还研究了制备FePtx磁性纳米颗粒的影响因素,如：沉积电位、Fe2+浓度、pH值、分散剂(PVP)和阴极选材等。研究结果表明：a)在沉积电位为-18V、pH值在2.5时,得到的是FePtx磁性纳米颗粒而不形成薄膜；b)电化学法制备FePtx磁性纳米颗粒时,沉积电位的影响是至关重要的；c)适当地使用PVP可以有效地改善FePtx磁性纳米颗粒的分散性。因此,最后得到制备FePtx磁性纳米颗粒时的最佳工艺条件：在适量分散剂的作用下,沉积电位为-18V,pH值为2.5。2)调整沉积电位为-7到-15V,使Fe和Pt能够尽可能的共同沉积在基体上制得FePtx磁性薄膜。在沉积电位为-11V、pH值为2.5时制得的FePtx薄膜较致密。SEM分析表明制备的由FePtx磁性纳米颗粒组成的FePtx薄膜厚度约为5μm；X射线衍射(XRD)分析表明制得的FePtx薄膜为FCC结构的(Fe, Pt)固溶体；VSM研究表明热处理后的FePtx薄膜转变为FCT结构,其矫顽力由零增加为150.00Oe。更多还原

【Abstract】 In this paper, FePtx nanoparticles (NPS) and nanoscale film (NF) were prepared via pulse electrodeposited method (PEM), where FeSO4·7H2O and H2PtCl6·6H2O were used as Fe resource and Pt resource, respectively. The PEM-derived FePtxx NPs and NF were subsequently characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) equipped with X-ray energy dispersive spectroscopy (EDX), and vibrating sample magnetometer (VSM). The results are given as following in detail:1) The X-ray powder diffraction (XRD) analysis indicated that a face-centered cubic (FCC) structure of FePtx NPs was obtained and its crystalline phase was transformed from FCC to L12 structure when the NPs were annealed at 700℃for 30 min under N2 atmosphere. The transmission electron microscopy (TEM) equipped with X-ray energy dispersive spectroscopy (EDX) results revealed that the FePtx particle sizes were averaged at 2.5 nm. The vibrating sample magnetometer (VSM) was used to determine the coercivities of PEM-derived and annealed FePtx NPs, which are significantly changed from zero to 150 Oe due to the formation of limited amount of FePtx with ordered phase of L10. In addition, the effect experimental factors, such as deposition potential, initial molar concentration of Fe2+, pH value, dispersant (PVP) and the cathode material, on the chemical composition and fine structure were investigated. The results show that:a) the FePtx NPs cannot construct the film under the condition of 18 V of potential and 2.5 of pH value; b) the potential has strong influence on the chemical composition of PEM-derived FePtx NPs; c) the addition of PVP can obviously improve the dispersion of the FePtx NPs. Thus, the optimum process for preparing the FePtx NPs was finally obtained: 18V of applied potential,2.5 of pH value, a certain quantity of PVP addition.2) The FePtx NF can be formed in the case of controlling the deposit potential in the range of 7-15V due to the synchronous depositions of Fe and Pt atoms. The most compact FePtx NF will be obtained under the condition of 11V of potential and 2.5 of pH value. SEM study shows that the thickness of the film built with FePtx NPs is approximate 5μm. The FePtx NF is of FCC structure of (Fe,Pt) sold solution, as shown in XRD analysis. VSM studies show that the coercivity of FePtx NF changes from zero to 150 Oe before and after annealing, implying limited amount of FePtx with ordered phase of L10 formed.更多还原