Kim Chang Woo, Kim In Ho, Kang Young Soo
Department of Smart Green Technology Engineering, Pukyong National University, Busan 48513, Republic of Korea; Department of Graphic Arts Information Engineering, College of Engineering, Pukyong National University, Busan 48513, Republic of Korea.
Korea Center for Artificial Photosynthesis and Department of Chemistry, Sogang University, Seoul 04107, Republic of Korea.
J Colloid Interface Sci. 2021 May;589:157-165. doi: 10.1016/j.jcis.2020.12.085. Epub 2020 Dec 28.
Magnetic spin exchange-coupled magnets have been investigated for obtaining an enhanced energy product, however, approaches at the nanoscale have been greatly restricted because of the lack of consideration of the relationships among the individual components. Here, we suggest a facile strategy for fabricating exchange-coupled nanomagnets with a large energy product. As a bottom-up approach, this work introduces a combined thermal decomposition and reduction/diffusion process to obtain a magnetic spin exchange coupled SmCo/Co nanocomposite magnet. The SmCo/Co nanocomposite magnet was fabricated through a three-step approach: (1) chemical synthesis of Co@SmO nanoparticles and Co nanoparticles as hard and soft magnetic phases, respectively, (2) 3-dimensional alternating arrangement of both magnetic phases and (3) a reduction/diffusion process for the magnetic spin exchange interaction. Our results demonstrate that an effective magnetic spin exchange interaction strongly depends on the dimension and arrangement of the hard and soft phases, which were synthetically tuned to be within the magnetic domain wall size.
为了获得更高的能量积，人们对磁自旋交换耦合磁体进行了研究，然而，由于缺乏对各个组件之间关系的考虑，纳米尺度的方法受到了很大限制。在此，我们提出了一种制备具有高能量积的交换耦合纳米磁体的简便策略。作为一种自下而上的方法，这项工作引入了热分解与还原/扩散相结合的过程，以获得磁自旋交换耦合的SmCo/Co纳米复合磁体。SmCo/Co纳米复合磁体通过三步法制备：（1）分别化学合成作为硬磁相和软磁相的Co@SmO纳米颗粒和Co纳米颗粒，（2）两种磁相的三维交替排列，以及（3）用于磁自旋交换相互作用的还原/扩散过程。我们的结果表明，有效的磁自旋交换相互作用强烈依赖于硬磁相和软磁相的尺寸和排列，通过合成调整使其处于磁畴壁尺寸范围内。
