| Elastic and thermodynamic properties of vanadium nitride under pressure and the effect of metallic bonding on its hardness |
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| 作者姓名： | 濮春英 周大伟 包代小 卢成 靳希联 宿太超 张飞武 |
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| 作者单位： | College |
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| 基金项目： | Project supported by the National Natural Science Foundation of China (Grant Nos.11247222,51001042,and 11174102);the Henan Joint Funds of the National Natural Science Foundation of China (Grant No.U1304612);the Natural Science Foundation of Education Department of Henan Province,China (Grant Nos.2011B140015 and 2010B140012);the China Postdoctoral Science Foundation (Grant No.20110491317);the Nanyang Normal University Science Foundation,China (Grant Nos.ZX2012018 and ZX2013019) |
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| 摘 要： | By the particle-swarm optimization method, it is predicted that tetragonal P42mc, 141md, and orthorhombic Amm2 phases of vanadium nitride （VN） are energetically more stable than NaCl-type structure at 0 K. The enthalpies of the predicted three new VN phases, along with WC, NaC1, AsNi, CsCl type structures, are calculated each as a function of pressure. It is found that VN exhibits the WC-to-CsCl type phase transition at 256 GPa. For the considered seven crystal- lographic VN phases, the structures, elastic constants, bulk moduli, shear moduli, and Debye temperatures are investigated. Our calculated equilibrium structural parameters are in very good agreement with the available experimental results and the previous theoretical results for the NaC1 phase. The Debye temperatures of VN predicted three novel phases, which are all higher than those of the remaining structures. The elastic constants, thermodynamic properties, and elastic anisotropies of VN under pressure are obtained and the mechanical stabilities are analyzed in detail based on the mechanical stability criteria. Moreover, the effect of metallic bonding on the hardness of VN is also investigated, which shows that VNs in P42mc, 141md, and Amm2 phases are potential superhard phases. Further investigation on the experimental level is highly recommended to confirm our calculations presented in this paper.
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| 关 键 词： | 热力学性质 弹性常数 氮化钒 压力 硬度 金属 结构参数 机械稳定性 |
| 收稿时间： | 2013-03-23 |
Elastic and thermodynamic properties of vanadium nitride under pressure and the effect of metallic bonding on its hardness |
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| Pu Chun-Ying,Zhou Da-Wei,Bao Dai-Xiao,Lu Cheng,Jin Xi-Lian,Su Tai-Chao,Zhang Fei-Wu.Elastic and thermodynamic properties of vanadium nitride under pressure and the effect of metallic bonding on its hardness[J].Chinese Physics B,2014,23(2):26201-026201. |
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| Authors: | Pu Chun-Ying Zhou Da-Wei Bao Dai-Xiao Lu Cheng Jin Xi-Lian Su Tai-Chao Zhang Fei-Wu |
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| Institution: | a College of Physics and Electronic Engineering, Nanyang Normal University, Nanyang 473061, China;b The School Hospital, Nanyang Normal University, Nanyang 473061, China;c State Key Laboratory of Superhard Materials, College of Physics, Jilin University, Changchun 130012, China;d Institute of Materials Science and Engineering, Henan Polytechnic University, Jiaozuo 454000, China;e Nanochemistry Research Institute, Curtin University, Perth, WA-6845, Australia |
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| Abstract: | By the particle-swarm optimization method,it is predicted that tetragonal P42mc,I41md,and orthorhombic Amm2phases of vanadium nitride(VN)are energetically more stable than NaCl-type structure at 0 K.The enthalpies of the predicted three new VN phases,along with WC,NaCl,AsNi,CsCl type structures,are calculated each as a function of pressure.It is found that VN exhibits the WC-to-CsCl type phase transition at 256 GPa.For the considered seven crystallographic VN phases,the structures,elastic constants,bulk moduli,shear moduli,and Debye temperatures are investigated.Our calculated equilibrium structural parameters are in very good agreement with the available experimental results and the previous theoretical results for the NaCl phase.The Debye temperatures of VN predicted three novel phases,which are all higher than those of the remaining structures.The elastic constants,thermodynamic properties,and elastic anisotropies of VN under pressure are obtained and the mechanical stabilities are analyzed in detail based on the mechanical stability criteria.Moreover,the effect of metallic bonding on the hardness of VN is also investigated,which shows that VNs in P42mc,I41md,and Amm2 phases are potential superhard phases.Further investigation on the experimental level is highly recommended to confirm our calculations presented in this paper. |
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| Keywords: | vanadium nitride elastic constants thermodynamic properties hardness |
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