强磁场辅助合成FePtCu纳米粒子及其有序结构调控

强磁场能够将高的磁化能量无接触地传递到材料的原子尺度,改变材料的热力学状态,影响原子和分子的排列、匹配、迁移等行为,因此本研究将强磁场引入到湿化学法中,合成高有序度的FePtCu纳米粒子。研究表明：磁场下制备的FePtCu纳米粒子呈球形,形貌、尺寸均一,分散度较好。随着磁场强度增加,FePtCu纳米粒子的尺寸增加,有序度(s)和矫顽力逐渐提高。在6 T强磁场下,获得了尺寸约为11 nm,s为0.8985的L10-FePtCu纳米粒子。强磁场对粒子的磁化作用造成晶格应变,导致空位或缺陷形成,从而有效加速Fe和Pt原子的有序扩散,促进了FePt纳米粒子的无序-有序转化。强磁场辅助可实现对有序结构的调控,该方法为直接制备L10结构纳米材料提供了一种新思路。关键词：强磁场；湿化学法；FePtCu；纳米粒子；有序结构

High Magnetic Field Assisted Synthesis of FePtCu Nanoparticles with Tunable Ordered Structure

High magnetic fields (HMF) can pass high intensity energies to the atomic scale of materials without contact to change the thermodynamic state of materials, and affect the arrangement, matching and migration of atoms and molecules. Therefore, in this work, HMF was introduced into wet-chemical synthesis to prepared FePtCu nanoparticles (NPs). The results show that the FePtCu NPs with L10 structure, uniform morphology, and good dispersibility were successfully prepared under HMF. The HMF increased the size, ordering degree s and the coercivity of the FePtCu NPs. The L10-FePtCu NPs with sizes of about 11 nm and ordering degree of 0.8985 were obtained under the HMF of 6 T. The HMF might magnetize the NPs and cause lattice distortions, which facilitates formation of vacancies or defects in the FePt NPs. A lot of vacancies are effectively accelerate the orderly diffusion of Fe and Pt atoms, and promoted the disordered-ordered transformation of the FePt NPs. Therefore, HMF assistance can accomplish the regulation of ordered structure. This method offers a new path for the direct synthesis of L10 structured nanomaterials.