AuCu籽晶界面诱导合成FeCo硬磁纳米粒子

Interface-induced method to synthesize FeCo hard magnetic nanoparticles by using AuCu seed crystal

FeCo纳米粒子是优良的磁性材料,具有重要的潜在应用价值。但通常制备的FeCo纳米材料矫顽力低,属于软磁材料。提出了一种新颖的湿化学方法合成FeCo硬磁纳米粒子:首先制备L1_(0)-AuCu籽晶纳米粒子,然后Fe、Co原子沉积在籽晶外层外延生长,获得具有核壳结构的AuCu@FeCo纳米粒子,利用有序结构的L1_(0)-AuCu籽晶界面,诱导FeCo外壳形成硬磁纳米粒子。AuCu籽晶粒子合成中,随着反应温度增加,AuCu籽晶逐渐从无序向有序转变,同时粒子的形貌和分散性也逐渐改善,在340℃时,获得了分散性好、有序度高的L1_(0)-AuCu籽晶纳米粒子;FeCo添加量对FeCo外壳的形貌和磁性能有重要影响,当FeCo添加量x=0.085 mmol时,获得了具有良好分散性的AuCu@FeCo硬磁纳米粒子,矫顽力达到605 Oe。提出的界面诱导法为制备良好分散性FeCo硬磁纳米粒子提供了一种新思路。

FeCo nanoparticles are excellent magnetic materials with important potential applications. Normally, the FeCo nanomaterials present low coercivity, which are soft magnetic materials. In order to prepare FeCo hard magnetic nanoparticles, a novel wet-chemical method is proposed. In this method, L1_(0)-AuCu seed particles were firstly prepared, and then Fe and Co atoms epitaxially grew on the surface of seed particles to form AuCu@FeCo core-shell nanoparticles. The ordered structure of L1_(0)-AuCu seed crystal interface could induce FeCo shells to form hard magnetic nanoparticles. In the synthesis of AuCu seed crystal particles, the AuCu seed crystals gradually changed from disorder to order, and the morphology and dispersion of the particles also gradually improved with the increase of reaction temperature. At 340 ℃, well-dispersed and highly ordered L1_(0)-AuCu seed crystals were obtained. The amount of FeCo addition has an important effect on the morphology and magnetic properties of FeCo shells. When the FeCo addition amount is x=0.085 mmol, the AuCu@FeCo hard magnetic nanoparticles with good dispersion and coercivity reached 605 Oe were obtained. The interfacial induction method provides a new idea for the preparation of FeCo hard magnetic nanoparticles with good dispersion and high coercivity.