Institute of Solid State Physics, University of Latvia, Kengaraga 8, Riga, LV-1063, Latvia.
St. Petersburg State University, 7/9 Universitetskaya nab., 199034, St. Petersburg, Russia.
Sci Rep. 2017 Sep 5;7(1):10579. doi: 10.1038/s41598-017-11236-7.
Bimetallic FePt nanoparticles with L1 structure are attracting a lot of attention due to their high magnetocrystalline anisotropy and high coercivity what makes them potential material for storage of ultra-high density magnetic data. FePt nanoclusters are considered also as nanocatalysts for growth of carbon nanotubes of different chiralities. Using the DFT-LCAO CRYSTAL14 code, we have performed large-scale spin-polarized calculations on 19 different polyhedral structures of FePt nanoparticles in order to estimate which icosahedral or hcp-structured morphology is the energetically more preferable. Surface energy calculations of all aforementioned nanoparticles indicate that the global minimum corresponds to the nanocluster possessing the icosahedron "onion-like" structure and FePt morphology where the outer layer consists of Pt atoms. The presence of the Pt-enriched layer around FePt core explains high oxidation resistance and environmental stability, both observed experimentally.
具有 L1 结构的双金属 FePt 纳米颗粒因其高磁各向异性和高矫顽力而备受关注，这使它们成为超高密度磁数据存储的潜在材料。FePt 纳米团簇也被认为是不同手性碳纳米管生长的纳米催化剂。我们使用 DFT-LCAO CRYSTAL14 代码，对 19 种不同的 FePt 纳米颗粒的多面体结构进行了大规模的自旋极化计算，以估算哪种二十面体或 hcp 结构形态在能量上更可取。对所有上述纳米颗粒的表面能计算表明，全局最小值对应于具有“洋葱状”二十面体结构和 FePt 形态的纳米团簇，其中外层由 Pt 原子组成。FePt 核周围存在富 Pt 层解释了实验中观察到的高抗氧化性和环境稳定性。
