Influence of chemical bonding and magnetism on elastic properties of the A2MB2 borides (A = Nb, Ta; M = Fe, Ru, Os) from first-principles calculations
Influence of chemical bonding and magnetism on elastic properties of the A2MB2 borides (A = Nb, Ta; M = Fe, Ru, Os) from first-principles calculations
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DOI：
10.1016/j.commatsci.2015.03.036
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发表时间：
2015-06
影响因子：
3.3
通讯作者：
R. Touzani;C. Rehorn;B. Fokwa
中科院分区：
文献类型：
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作者：
R. Touzani;C. Rehorn;B. Fokwa
在密度泛函理论（DFT）框架下研究了A2 FeB 2（A = Nb，Ta，Mo 2FeB 2型结构）及其高级同系物A2 OsB 2和预测的“A2 RuB 2”（均具有Nb 2 OsB 2型结构）的弹性性质.研究了磁性、成键和电子结构对A_2MB_2系列（A = Nb，Ta; M = Fe，Ru，Os）弹性性质的影响。Ta_2FeB_2与Nb_2FeB_2、Mo_2FeB_2一样具有反铁磁性。磁性对Nb_2FeB_2和Ta_2FeB_2的弹性性质的影响与Mo_2FeB_2的不同，但影响的方式相似。我们预测三元A2 MB 2（A = Nb，Ta; M = Ru，Os）二硼化物具有可比的二元硬和超不可压缩的二硼化物RuB 2和OsB 2的机械性能。一般来说，在这些三元二硼化物中，体积模量受化学键强度的严重影响（积分晶体轨道汉密尔顿布居：ICOHP），而剪切模量主要受费米能级在态密度中的位置的影响。
The elastic properties of A2FeB2(A = Nb, Ta, Mo2FeB2-type structure) and their higher homologues A2OsB2and the predicted “A2RuB2” (both with Nb2OsB2-type structure) have been investigated within the density functional theory (DFT) framework. Furthermore, the influence of magnetism, bonding and electronic structure on the elastic properties in the A2MB2series (A = Nb, Ta; M = Fe, Ru, Os) was studied. Ta2FeB2is predicted to order antiferromagnetically just like Nb2FeB2and Mo2FeB2. Magnetism affects the elastic properties of both Nb2FeB2and Ta2FeB2in a similar manner, but different from Mo2FeB2. We predict the ternary A2MB2(A = Nb, Ta; M = Ru, Os) diborides to have comparable mechanical properties as the binary hard and ultraincompressible diborides RuB2and OsB2. In general in these ternary diborides, the bulk modulus is heavily influenced by the strength of the chemical bonding (Integrated Crystal Orbital Hamilton Population: ICOHP) while the shear modulus is mainly affected by the position of the Fermi level in the density-of-states.