Shankhari Pritam, Janka Oliver, Pöttgen Rainer, Fokwa Boniface P T
Department of Chemistry, University of California, Riverside, California 92521, United States.
Anorganische Festkörperchemie, Universität des Saarlandes, Campus C 4 1, D-66123 Saarbrücken, Germany.
J Am Chem Soc. 2021 Mar 24;143(11):4205-4212. doi: 10.1021/jacs.0c10778. Epub 2021 Mar 9.
Designing new rare-earth-free (REF) permanent magnetic materials (PMM) to replace the high performing but critically restrained rare-earth-based PMM remains a great challenge to the scientific community. Here, we report on the rational design of new REF PMM, HfIrB ( = Fe, Mn) via a theory-experiment combined approach. Density functional theory (DFT) predicted strong interchain - spin-exchange coupling and large magnetocrystalline anisotropy energies () for the new compounds, suggesting potential intrinsic PMM properties. Subsequent experimental bulk syntheses and magnetic characterizations established the highest ordering temperature ( ∼ 900 K) for HfFeIrB and the highest intrinsic coercivity () value for HfMnIrB ( = 62.1 kA/m) reported to date for TiCoB-type compounds. Importantly, at room temperature both phases show significant coercivities due to intrinsic factors only, hinting at their huge potential to create REF PMM by improving extrinsic factors such as controlling the microstructure and the domain orientation.
设计新型无稀土（REF）永磁材料（PMM）以取代高性能但受到严格限制的稀土基永磁材料，对科学界来说仍然是一个巨大的挑战。在此，我们报告通过理论 - 实验相结合的方法对新型REF永磁材料HfIrB（ = Fe，Mn）进行的合理设计。密度泛函理论（DFT）预测新化合物具有强链间 - 自旋交换耦合和大的磁晶各向异性能量（），表明其具有潜在的本征永磁性能。随后的实验体相合成和磁性表征确定了HfFeIrB的最高有序温度（约900 K）以及HfMnIrB（ = 62.1 kA/m）的最高本征矫顽力（）值，这是迄今为止报道的TiCoB型化合物中的最高值。重要的是，在室温下，两个相仅由于本征因素就显示出显著的矫顽力，这暗示了通过改善外在因素（如控制微观结构和畴取向）来制造REF永磁材料的巨大潜力。
