Pb元素诱导高有序度L1_(0)-FePt纳米粒子的一步合成

One step synthesis of highly ordered L1_(0)-FePt nanoparticles induced by Pb

面心四方相(L1_(0))结构的FePt纳米粒子具有较大的磁晶各向异性,生物相容性好,催化活性高的特点,在信息储存、军事、催化剂、永磁体和生物医学等领域具有广阔的应用前景。研究表明,在制备L1_(0)-FePt纳米粒子的过程中,添加Au、Ag、Cu等贵金属或过渡族金属元素,可以简化制备过程,同时显著降低L1_(0)-FePt纳米粒子的无序-有序转变温度,诱导高有序度L1-FePt纳米粒子的一步合成。掺杂第三金属元素Pb,通过湿化学法直接合成出成分均匀、无团聚还具有高有序度和良好磁性能的L1_(0)-FePt纳米粒子。结果表明,随着反应温度的升高,L1_(0)-FePt纳米粒子的有序度s和矫顽力H。均逐渐增加。实验最佳制备合成温度为360℃,可制得磁性能最佳的L1_(0)-FePt纳米粒子。此时,纳米粒子的原子组分为Fe_(62)Pt_(15)Pb_(23),酸洗后矫顽力,H_(c)=8622.4Oe。因此,合理的合成工艺和第三元素诱导可直接合成出高有序和良好分散性的L1_(0)-FePt纳米粒子。Pb元素诱导高有序度L1_(0)-FePt纳米粒子的一步合成工艺有望实现高有序度L1-FePt纳米粒子的可控制备。

FePt nanoparticles with face centered tetragonal phase(Ll.)structure have the characteristics of large Magnetocrystalline anisotropy,good biocompatibility and high catalytic activity,and have broad application prospects in the fields of information storage,military,catalysts,permanent magnets and biomedicine.The research shows that the addition of precious metals or transition metal elements such as Au,Ag,Cu can simplify the preparation process,significantly reduce the disorder order transition temperature of L1_(0)-FePt nanoparticles,and induce the one-step synthesis of highly ordered L1_(0)-FePt nanoparticles.We doped the third metal element Pb,and directly synthesized L1_(0)-FePt nanoparticles with uniform composition,no agg1_(0)meration,high order and good magnetic properties through wet chemical method.The results showed that the ordering degree s and coercivity Hc of L1_(0)-FePt nanoparticles increased with the increase of reaction temperature.The best synthesis temperature is 36o C,and L1_(0)-FePt nanoparticles with the best magnetic properties can be prepared.At this time,the atomic composition of the nanoparticles is Fe_(62) Pt_(15) Pb_(23),and the coercivity after pickling is H_(c)=8622.4 Oe.Therefore,L1_(0)-FePt nanoparticles with high order and good dispersion can be directly synthesized by a reasonable synthesis process and the induction of the third element.The one-step synthesis process of Pb elements is expected to achieve the controllable preparationof L1_(0)-FePtnanoparticles.