Phase stability and mechanical properties of niobium nitrides
Phase stability and mechanical properties of niobium nitrides
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DOI：
10.1103/physrevb.82.054109
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发表时间：
2010-08
影响因子：
3.7
通讯作者：
V. Ivashchenko;P. Turchi;E. Olifan
中科院分区：
文献类型：
--
作者：
V. Ivashchenko;P. Turchi;E. Olifan
用第一性原理赝势计算方法研究了氮化Nb各相的结构稳定性。根据电子结构和声子计算的结果，分析了NaCl型、NiAs型、AsNi型和CW型NbN相、亚化学计量比${\Text{Nb}}_{8}{\Text{N}}_{7}$、${\Text{Nb}}_{4}{\Text{N}}_{3}和${\Text{Nb}}_{32}{\Text{N}}{31}$化合物的稳定性。研究了这些结构在单轴拉伸应变下的行为。讨论了软声子模的电子来源和氮化Nb的力学性质。
First-principles pseudopotential calculations were performed to investigate the structural stability of various phases of niobium nitrides ${\text{NbN}}_{x}$. The stability of the NaCl-, NiAs-, AsNi-, and CW (anti--WC)-type NbN phases, the substoichiometric ${\text{Nb}}_{8}{\text{N}}_{7}$, ${\text{Nb}}_{4}{\text{N}}_{3}$, and ${\text{Nb}}_{32}{\text{N}}_{31}$ compounds are analyzed on the basis of the results of electronic structure and phonon calculations. The behavior of these structures under uniaxial tensile strain was investigated. The electronic origin of the soft phonon modes and the mechanical properties of niobium nitrides are discussed.