Exploring the elastic and electronic properties of chromium molybdenum diboride alloys
Exploring the elastic and electronic properties of chromium molybdenum diboride alloys
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DOI：
10.1016/j.jallcom.2021.158885
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发表时间：
2021-06
影响因子：
6.2
通讯作者：
Viviana Dovale-Farelo;P. Tavadze;M. Verstraete;A. Bautista-Hernández;A. Romero
中科院分区：
文献类型：
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作者：
Viviana Dovale-Farelo;P. Tavadze;M. Verstraete;A. Bautista-Hernández;A. Romero
我们用第一性原理计算研究了Cr1MoxB2forx=−= 的结构、力学、热、电和磁性质。基于结构搜索方法，我们确定了每个浓度的基态结构。该三元系为单斜晶系(x= 0.2 5，0.75)或三角晶系(x= 0.33，0.5 0，0.6 7)。计算的力学性能表明，当x=−0.50时，Cr1- -xMoxB2的强度最大。Cr0.5Mo0.5B2具有优良的力学性能(B=298 Gpa，Y=558 Gpa，G=235 Gpa，ν= 0.19，Hv=27 Gpa)，以较低的成本超过了β-MoB2。所有这些三元系都是维氏硬度大于24 Gpa的硬质合金。化学键分析表明，新化合物的强度与交替的平面和弯曲的B-B层以及较强的TM-B键有关。Cr0.5Mo0.5B2的强度提高是由于在费米能级附近形成了高密度的层间强的铬-钼金属键。
We perform first-principles calculations to study the structural, mechanical, thermal, electronic, and magnetic properties of Cr1−xMoxB2forx= 0.25, 0.33, 0.50, 0.67 and 0.75. Based on structural search methods, we determine the ground-state structure for each concentration. The ternaries are either monoclinic (x= 0.25, 0.75) or trigonal (x= 0.33, 0.50, 0.67). The calculated mechanical properties reveal that the strength of Cr1−xMoxB2is maximized forx= 0.50. Cr0.5Mo0.5B2exhibits excellent mechanical properties (B = 298 GPa, Y = 558 GPa, G = 235 Gpa,ν= 0.19,Hv=27 GPa), surpassing those ofβ-MoB2at a lower cost. All of these ternaries are hard alloys with Vickers hardness greater than 24 GPa. Chemical bonding analysis demonstrates that the strength of the new compounds is related to the alternating planar and buckled B-B layers, as well as the strong TM-B bonds. The enhanced strength of Cr0.5Mo0.5B2is a consequence of the high density of strong interlayer Cr-Mo metallic bonds around the Fermi level.