Prediction of Van Hove singularity systems in ternary borides
Prediction of Van Hove singularity systems in ternary borides
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DOI：
10.1038/s41524-023-01156-8
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发表时间：
2023-10-28
影响因子：
9.7
通讯作者：
Antropov，Vladimir
中科院分区：
文献类型：
--
作者：
Sun，Yang;Zhang，Zhen;Antropov，Vladimir
对三元α和β相(A=Mg，Ca，Sr，Ba，Al，Ga和Zn，Tis3dor4d过渡元素)的稳定结构进行了计算研究。我们发现，α-ATB4化合物a=Mg，Ca，Al，T= ，V，Cr，Mn，Fe，Ni，Co形成了一族结构稳定或几乎稳定的材料。这些体系在非磁性状态下是金属的，其特征是形成了三维过渡金属原子二聚体的定域类分子态，这导致了电子光谱中出现大量的Van Hove奇点。这种奇点与费米能级的接近程度可以很容易地通过电子掺杂来调节。对于位于中间的原子(铬、锰和铁)，这些奇点导致了磁不稳定性和具有弱金属或半导体性质的磁基态。这种状态表现为由3个元素的磁性二聚体形成的不同自旋梯子的非平凡共存。这些磁性状态可以被表征为自旋玻璃态的类似。讨论了生产镁铁硼的实验尝试和相关的挑战，并提出了进一步合成研究的有前途的方向。
A computational search for stable structures among both α and β phases of ternary ATB4borides (A= Mg, Ca, Sr, Ba, Al, Ga, and Zn,Tis3dor4dtransition elements) has been performed. We found that α-ATB4compounds withA= Mg, Ca, Al, andT= V, Cr, Mn, Fe, Ni, and Co form a family of structurally stable or almost stable materials. These systems are metallic in non-magnetic states and characterized by the formation of the localized molecular-like state of3dtransition metal atom dimers, which leads to the appearance of numerous Van Hove singularities in the electronic spectrum. The closeness of such singularities to the Fermi level can be easily tuned by electron doping. For the atoms in the middle of the3drow (Cr, Mn, and Fe), these singularities led to magnetic instabilities and magnetic ground states with a weakly metallic or semiconducting nature. Such states appear as non-trivial coexistence of the different spin ladders formed by magnetic dimers of3delements. These magnetic states can be characterized as an analog of the spin glass state. Experimental attempts to produce MgFeB4and associated challenges are discussed, and promising directions for further synthetic studies are formulated.