Electronic structure, bonding, and ground-state properties of AlB2-type transition-metal diborides -: art. no. 045115
Electronic structure, bonding, and ground-state properties of AlB2-type transition-metal diborides -: art. no. 045115
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DOI：
10.1103/physrevb.63.045115
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发表时间：
2001-01-15
影响因子：
3.7
通讯作者：
Asokamani, R
中科院分区：
文献类型：
--
作者：
Vajeeston, P;Ravindran, P;Asokamani, R
研究了AIB(2)型过渡金属二硼化物TMB2 （TM = Sc, Ti）的电子结构和基态性质。V, Cr, Mn, Fe， Y, Zr, Nb, Mo, Hf, Ta)用自洽紧密结合线性松饼锡轨道法计算。计算了这些体系的平衡体积、体积模量（B-0）、体积模量的压力导数（B-0’）、结合能（E-coh）、生成热（DeltaH）和电子比热系数（gamma），并与已有的实验和其他理论结果进行了比较。通过态密度直方图和电荷密度图分析了这些二硼化物的成键性质，并利用能带填充原理分析了它们的化学稳定性。计算得到的这些材料的粘性固有结的变化与带填充效应有关。赝隙的存在是所有这些化合物的共同特征。赝隙产生的原因是由于硼p态之间的强共价相互作用。我们对CrB2、MnB2和FeB2进行了自旋极化计算，发现MnB2和CrB2存在有限磁矩，而FeB2是非磁性的。
The electronic structure and ground state properties of AIB(2) type transition metal diborides TMB2 (TM = Sc, Ti. V, Cr, Mn, Fe, Y, Zr, Nb, Mo, Hf, Ta) have been calculated using the self consistent tight-binding linear muffin-tin orbital method. The equilibrium volume, bulk moduli (B-0), pressure derivative of bulk moduli (B-0'), cohesive energy (E-coh) heat of formation (DeltaH), and electronic specific heat coefficient (gamma) are calculated for these systems and compared with the available experimental and other theoretical results. The bonding nature of these diborides is analyzed via the density of states (DOS) histogram as well as the charge density plots, and the chemical stability is analyzed using the band filling principle. The variation in the calculated cohesive proper ties of these materials is correlated with the band filling effect. The existence of a pseudogap in the total density of states is found to be a common feature for all these compounds. The reason for the creation of the pseudogap is found to be due to the strong covalent interaction between boron p states. We have made spin polarized calculations for CrB2, MnB2, and FeB2 and found that finite magnetic moments exist fur MnB2 and CrB2 whereas FeB2 is nonmagnetic.