First-principles Study of Transition Metal Monoboride TMB

doi:10.19596/j.cnki.1001-246x.7860

Abstract

Abstract: We study thermodynamic stability, mechanical properties, and microscopic mechanisms of transition metal monoboride TMB (take TiB, VB and CrB in 3d series; ZrB, NbB and MoB in 4d series; HfB, TaB and WB in 5d series as examples) by first-principles calculations based on density functional theory and plane pseudopotential wave method. We found thermodynamic stability and hardness anomalies of transition metal monoborides. In particular, as valence electron concentration is 8 e·(f.u.)^-1, thermodynamic stability is the most stable and hardness is the highest. To reveal its mechanism, we calculated electronic structure of TMB. As valence electron concentration of TMB is at 8 e·(f.u.)^-1, covalent bonding of pd blocked effectively dislocation slipping between metal bilayers, prevented shear deformation, and resulted in high hardness. These discoveries may help new superhard material designs.

Key words: transition metal monoboride TMB, first-principles, hardness anomaly, microscopic mechanism

CLC Number:

O481
O482

QIN Ping, GAO Zhenbang, LIU Haidi, CHEN Yingcai. First-principles Study of Transition Metal Monoboride TMB[J]. CHINESE JOURNAL OF COMPUTATIONAL PHYSICS, 2019, 36(4): 491-497.

References

[1] LU C, LI Q, MA Y, et al. Extraordinary indentation strain stiffening produces superhard tungsten nitrides[J]. Phys Rev Lett, 2017, 119:115503.
[2] CUMBERLAND R W, WEINBERGER M B, GILMAN J J, et al. Osmium diboride, an ultra-incompressible, hard material[J]. J Am Chem Soc, 2005, 127:7264.
[3] LIANG Y C, YANG J, YUAN X, et al. Polytypism in superhard transition-metal triborides[J]. Sci Rep, 2014, 4:5063.
[4] ZEIRINGER I, ROGL P, GRYTSIV A, et al. Crystal structure of W_1-xB₃ and phase equilibria in the boron-rich part of the systems Mo-Rh-B and W-{Ru, Os, Rh, Ir, Ni, Pd, Pt}-B[J]. Phase Equilib Diff, 2014, 35:384.
[5] TAO Q, ZHENG D, ZHAO X, et al. Exploring hardness and the distorted sp² hybridization of B-B bonds in WB₃[J]. Chem Mater, 2014, 26:5297.
[6] LECH A T, TURNER C L, MOHAMMADI R, et al. Structure of superhard tungsten tetraboride:A missing link between MB₂ and MB₁₂ higher borides[J]. Proc Natl Acad Sci USA, 2015, 112:3223.
[7] KNAPPSCHNEIDER A, LITTERSCHEID C, GEORGE N C, et al. Peierls-distorted monoclinic MnB₄ with a Mn-Mn bond[J]. Angew Chem Int Ed, 2014, 53:1684.
[8] LIANG Y C, YUAN X, GAO Y, et al. Phonon-assisted crossover from a nonmagnetic Peierls insulator to a magnetic Stoner metal[J]. Phys Rev Lett, 2014, 113:176401.
[9] GOU H, DUBROVINSKAIA N, BYKOVA E, et al. Discovery of a superhard iron tetraboride superconductor[J]. Phys Rev Lett, 2013, 111:157002.
[10] AKOPOV G, YEUNG M T, SOBELL Z, et al. Superhard mixed transition metal dodecaborides[J]. Chem Mater, 2016, 28:6605.
[11] YEUNG M T, LEI J, MOHAMMADI R, et al. Superhard monoborides:Hardness enhancement through alloying in W_1-xTa_xB[J]. Adv Mater, 2016, 28:6993-6998.
[12] YEUNG M T, AKOPOV G, LIN C W, et al. Superhard W_0.5Ta_0.5B nanowires prepared at ambient pressure[J]. Appl Phys Lett, 2016, 109:203107.
[13] PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple[J]. Phys Rev Lett, 1996, 77:3865.
[14] KRESSE G, FURTHMULLER J. Characterization of carbon-carbon bonds on the SiC(001) c(2×2) surface[J]. Phys Rev B, 1996, 541(15):66308-10307.
[15] MONKHORST H J, PACK J D. Special points for Brillouin-zone integrations[J]. Phys Rev B, 1976, 13:5188.
[16] NIU X P, SUN Z L. First principles study on elastic and thermodynamic properties of CaS[J]. Chinese Journal of Computational Physics, 2017, 34(4):468-474.
[17] LIU X J, REN Y. Solid solution structure and elastic modulus of single atom in transition metal nitrides:First principle studies[J]. Chinese Journal of Computational Physics, 2013,30(3):433-440.
[18] XU X, FU K, LI L, et al. Dependence of the elastic properties of the early-transition-metal monoborides on their electronic structures:A density functional theory study[J]. Physica B:Condensed Matter, 2013, 419(21):105-111.
[19] 漆晨进. 高速钢中金属硼化物力学性质的第一性原理计算[D]. 昆明:昆明理工大学, 2014.
[20] 孙勇. 过渡金属硼化物的相稳定性和物理性能的第一性原理计算[D]. 呼和浩特:内蒙古工业大学, 2016.
[21] ELCORO L, ETXEBARRIA J. Common misconceptions about the dynamical theory of crystal lattices:Cauchy relations, lattice potentials and infinite crystals[J]. European Journal of Physics, 2011, 32(1):25.
[22] YEUNG M T, LEI J, MOHAMMADI R, et al. Superhard monoborides:Hardness enhancement through alloying in W_1-xTa_xB[J]. Advanced Materials, 2016, 28(32):6993-6998.