Bond deformation paths and electronic instabilities of ultraincompressible transition metal diborides: Case study of OsB2 and IrB2

被引：19

作者：

Zhang, R. F. ^{[1
,2
,3
,4
]}

Legut, D. ^{[5
]}

Wen, X. D. ^{[3
,6
,7
]}

Veprek, S. ^{[8
]}

Rajan, K. ^{[4
]}

Lookman, T. ^{[3
]}

Mao, H. K. ^{[9
,10
]}

Zhao, Y. S. ^{[11
]}

机构：

[1] Beihang Univ, Sch Mat Sci & Engn, Beijing 100191, Peoples R China

[2] Beihang Univ, Int Res Inst Multidisciplinary Sci, Beijing 100191, Peoples R China

[3] Los Alamos Natl Lab, Div Theoret, Los Alamos, NM 87545 USA

[4] Iowa State Univ, Dept Mat Sci & Engn, Ames, IA 50010 USA

[5] Tech Univ Ostrava, Nanotechnol Ctr, CZ-70833 Ostrava, Czech Republic

[6] Chinese Acad Sci, Inst Coal Chem, State Key Lab Coal Convers, Taiyuan 030001, Shanxi, Peoples R China

[7] Synfuels China, Beijing 100195, Peoples R China

[8] Tech Univ Munich, Dept Chem, D-85747 Garching, Germany

[9] Carnegie Inst Sci, Geophys Lab, Washington, DC 20015 USA

[10] Ctr High Pressure Sci & Technol Adv Res, Shanghai 201203, Peoples R China

[11] Univ Nevada, Dept Phys & Astron, HiPSEC, Las Vegas, NV 89154 USA

来源：

PHYSICAL REVIEW B | 2014年 / 90卷 / 09期

关键词：

SUPERHARD MATERIALS; CRYSTAL-STRUCTURES; OSMIUM DIBORIDE; HARD MATERIAL; 1ST-PRINCIPLES; DESIGN;

D O I：

10.1103/PhysRevB.90.094115

中图分类号：

T [工业技术];

学科分类号：

08 ;

摘要：

The energetically most stable orthorhombic structure of OsB2 and IrB2 is dynamically stable for OsB2 but unstable for IrB2. Both diborides have substantially lower shear strength in their easy slip systems than their metal counterparts. This is attributed to an easy sliding facilitated by out-of-plane weakening of metallic Os-Os bonds in OsB2 and by an in-plane bond splitting instability in IrB2. A much higher shear resistance of Os-B and B-B bonds than Os-Os ones is found, suggesting that the strengthened Os-B and B-B bonds are responsible for hardness enhancement in OsB2. In contrast, an in-plane electronic instability in IrB2 limits its strength. The electronic structure of deformed diborides suggests that the electronic instabilities of 5d orbitals are their origin of different bond deformation paths. Neither IrB2 nor OsB2 can be intrinsically superhard.

引用

页数：6

共 39 条

[1]

Bader R. F. W., 1994, ATOMS MOL QUANTUM TH

[2] What-does 'harder than diamond' mean? [J].

Brazhkin, V ;

Dubrovinskaia, N ;

Nicol, A ;

Novikov, N ;

Riedel, R ;

Solozhenko, R ;

Zhao, Y .

NATURE MATERIALS, 2004, 3 (09) :576-577

[3] Electronic and structural origin of ultraincompressibility of 5d transition-metal diborides MB2 (M=W, re, os) [J].

Chen, Xing-Qiu ;

Fu, C. L. ;

Krcmar, M. ;

Painter, G. S. .

PHYSICAL REVIEW LETTERS, 2008, 100 (19)

[4] Synthesis of ultra-incompressible superhard rhenium diboride at ambient pressure [J].

Chung, Hsiu-Ying ;

Weinberger, Michelle B. ;

Levine, Jonathan B. ;

Kavner, Abby ;

Yang, Jenn-Ming ;

Tolbert, Sarah H. ;

Kaner, Richard B. .

SCIENCE, 2007, 316 (5823) :436-439

[5]

Cotton T. A., 1972, ADV INORGANIC CHEM

[6] Osmium diboride, an ultra-incompressible, hard material [J].

Cumberland, RW ;

Weinberger, MB ;

Gilman, JJ ;

Clark, SM ;

Tolbert, SH ;

Kaner, RB .

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, 2005, 127 (20) :7264-7265

[7] Accuracy of ab initio methods in predicting the crystal structures of metals:: A review of 80 binary alloys [J].

Curtarolo, S ;

Morgan, D ;

Ceder, G .

CALPHAD-COMPUTER COUPLING OF PHASE DIAGRAMS AND THERMOCHEMISTRY, 2005, 29 (03) :163-211

[8]

Curtarolo S, 2013, NAT MATER, V12, P191, DOI [10.1038/nmat3568, 10.1038/NMAT3568]

[9]

FIZ/NIST, 2009, IN CRYST STRUCT DAT

[10] Hardness of covalent crystals [J].

Gao, FM ;

He, JL ;

Wu, ED ;

Liu, SM ;

Yu, DL ;

Li, DC ;

Zhang, SY ;

Tian, YJ .

PHYSICAL REVIEW LETTERS, 2003, 91 (01)

← 1 2 3 4 →