Magnetism of new metastable cobalt-nitride compounds
Magnetism of new metastable cobalt-nitride compounds
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DOI：
10.1039/c8nr02105h
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发表时间：
2018-07-21
期刊：
影响因子：
6.7
通讯作者：
Sellmyer, David J.
中科院分区：
文献类型：
--
作者：
Balasubramanian, Balamurugan;Zhao, Xin;Sellmyer, David J.
寻找具有高磁化强度和磁晶各向异性的新型磁性材料对于包括信息和能源处理在内的广泛应用具有重要意义。只有有限数量的天然磁性化合物是合适的。这种情况激发了对远离热平衡条件的新相的探索，但由于较高的正地层能量，它们的稳定性通常受到抑制。在这里，一种纳米团簇沉积方法使得一组新的非平衡态Co- N金属间化合物得以发现。利用自适应遗传算法和电子结构计算等计算方法辅助实验搜索。传统观点认为，N在Co中的间隙溶解度或取代溶解度比在Fe中的溶解度低得多，平衡态合金中N在Co中的溶解度不会产生具有显著磁化和各向异性的材料。相比之下，我们的实验发现了具有良好磁性能的新型Co- N化合物，包括具有高饱和磁极化（Js = 1.28 T或12.8 kG）和可观的单轴磁晶各向异性（K1 = 1.01 MJ m- 3或10.1 Mergs / cm3）的六方Co3N纳米颗粒。这项研究为发现新的磁性化合物提供了一条超越现有材料数据库的计算效率的途径，这对未来的技术具有重要意义。
The search for new magnetic materials with high magnetization and magnetocrystalline anisotropy is important for a wide range of applications including information and energy processing. There is only a limited number of naturally occurring magnetic compounds that are suitable. This situation stimulates an exploration of new phases that occur far from thermal- equilibrium conditions, but their stabilization is generally inhibited due to high positive formation energies. Here a nanocluster- deposition method has enabled the discovery of a set of new non- equilibrium Co- N intermetallic compounds. The experimental search was assisted by computational methods including adaptive- genetic- algorithm and electronicstructure calculations. Conventional wisdom is that the interstitial or substitutional solubility of N in Co is much lower than that in Fe and that N in Co in equilibrium alloys does not produce materials with significant magnetization and anisotropy. By contrast, our experiments identify new Co- N compounds with favorable magnetic properties including hexagonal Co3N nanoparticles with a high saturation magnetic polarization ( Js = 1.28 T or 12.8 kG) and an appreciable uniaxial magnetocrystalline anisotropy ( K1 = 1.01 MJ m- 3 or 10.1 Mergs per cm3). This research provides a pathway for uncovering new magnetic compounds with computational efficiency beyond the existing materials database, which is significant for future technologies.