Ma Shuailing, Farla Robert, Bao Kuo, Tayal Akhil, Zhao Yongsheng, Tao Qiang, Yang Xigui, Ma Teng, Zhu Pinwen, Cui Tian
Synergetic Extreme Condition High-Pressure Science Center, State Key Laboratory of Superhard Materials, college of physics, Jilin University, Changchun 130012, China.
Deutsches Elektronen-Synchrotron DESY, Notkestrasse, 85, 22607, Hamburg, Germany.
Nanoscale. 2021 Nov 18;13(44):18570-18577. doi: 10.1039/d1nr03984a.
The combination of various desired physical properties greatly extends the applicability of materials. Magnetic materials are generally mechanically soft, yet the combination of high mechanical hardness and ferromagnetic properties is highly sought after. Here, we report the synthesis and characterization of nanocrystalline manganese boride, CrB-type MnB, using the high-pressure and high-temperature method in a large volume press. CrB-type MnB shares the specificity of large numbers of unpaired electrons of manganese ions and strong covalent boron zigzag chains. Thus, manganese mono-boride exhibits "strong" ferromagnetic, magnetocaloric behavior, and possesses high Vickers hardness. We demonstrate that zigzag boron chains in this structure not only play a pivotal role in strengthening mechanical properties but also tuning the exchange correlations between manganese atoms. Nontoxic and Earth-abundant CrB-type MnB is much more incompressible and tougher than traditional ferromagnetic materials. The unique combination of high mechanical hardness, magnetism, and electrical conductivity properties makes it a particularly promising candidate for a wide range of applications.
各种所需物理性质的结合极大地扩展了材料的适用性。磁性材料通常机械性能较软，但兼具高机械硬度和铁磁性能的材料备受追捧。在此，我们报道了在大体积压机中采用高压高温法合成并表征纳米晶硼化锰CrB型MnB。CrB型MnB具有锰离子大量未成对电子以及强共价键硼之字形链的特性。因此，一硼化锰表现出“强”铁磁性、磁热效应行为，并具有高维氏硬度。我们证明，该结构中的之字形硼链不仅在强化机械性能方面起关键作用，而且还能调节锰原子之间的交换关联。无毒且储量丰富的CrB型MnB比传统铁磁材料更难压缩且更坚韧。高机械硬度、磁性和导电性的独特组合使其成为广泛应用中特别有前景的候选材料。
