Mechanical and metallic properties of tantalum nitrides from first-principles calculations

Li, Da; Tian, Fubo; Duan, Defang; Bao, Kuo; Chu, Binhua; Sha, Xiaojing; Liu, Bingbing; Cui, Tian

doi:10.1039/c3ra46734a

Cited by 57 publications

(23 citation statements)

References 50 publications

(50 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…18 On the other hand, first-principles pseudopotential plane-wave method has been proved to be a useful tool for understanding the physics of wide materials. 29 ) systems. Our previous studies have proved the validity of above methods in not only clarifying the structures but also in discovering new materials toward typical binary TM -LE systems, such as in developing the low-temperature phase diagrams of W-N, 26 Re-N, 27 Tc-N, 28 and Ta-N (ref.…”

Section: Introductionmentioning

confidence: 99%

Phase diagram, mechanical properties, and electronic structure of Nb–N compounds under pressure

Zhao

Bao

Tian

et al. 2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

Niobium-nitrogen compounds, which are potential candidates for superhard multifunctional materials, may possess multiple stoichiometries and structures under pressure. Based on ab initio evolutionary structural searches, we predict three ground states (oP6-Nb2N, CW-NbN, and hP22-Nb5N6) and six stable high pressure phases (ε-NbN, AsNi-NbN, U2S3-Nb2N3, oC24-NbN2, mP8-NbN3, and mP20-NbN4) for Nb-N compounds at pressures up to 100 GPa. Among them, the oP6-Nb2N, oC24-NbN2, mP8-NbN3, and mP20-NbN4 have never been reported, and N-rich oC24-NbN2, mP8-NbN3, and mP20-NbN4 high pressure phases are recoverable to ambient pressure. We find that the structure of N-rich Nb-N compounds consists of NbNx polyhedral stacking configurations and connected with Nn (n = 2, 3, 4, and n) polymerizations, which can remarkably improve the elastic modulus. It is found that CW-NbN and mP20-NbN4 are two potential ultra-incompressible and hard materials with the hardness calculated to be 24.56 and 19.86 GPa, respectively, while other N-rich phases such as U2S3-Nb2N3, oC24-NbN2, and mP8-NbN3 are soft materials. Detailed electronic structure and chemical bonding analysis proved that the high hardness of CW-NbN and mP20-NbN4 stems from the strong covalent bonding and the fullfilled Nb-N bonding and antibonding states.

show abstract

Section: Introductionmentioning

confidence: 99%

Phase diagram, mechanical properties, and electronic structure of Nb–N compounds under pressure

Zhao

Bao

Tian

et al. 2015

Phys. Chem. Chem. Phys.

Self Cite

View full text Add to dashboard Cite

show abstract

“…The phonon calculations were carried out by using a supercell approach as implemented in the PHONON code41. The details of convergence tests have been described elsewhere42434445.…”

Section: Discussionmentioning

confidence: 99%

Structural, mechanical and electronic properties of Rh2B and RhB2: first-principles calculations

Chu

Tian

et al. 2015

Sci Rep

Self Cite

View full text Add to dashboard Cite

The crystal structures of Rh2B and RhB2 at ambient pressure were explored by using the evolutionary methodology. A monoclinic P21/m structure of Rh2B was predicted and donated as Rh2B-I, which is energetically much superior to the previously experimentally proposed Pnma structure. At the pressure of about 39 GPa, the P21/m phase of Rh2B transforms to the C2/m phases. For RhB2, a new monoclinic P21/m phase was predicted, named as RhB2-II, it has the same structure type with Rh2B. Rh2B-I and RhB2-II are both mechanically and dynamically stable. They are potential low compressible materials. The analysis of electronic density of states and chemical bonding indicates that the formation of strong and directional covalent B-B and Rh-B bonds in these compounds contribute greatly to their stabilities and high incompressibility.

show abstract

“…[29] Theoretical studies show that aN /Tar atio of 5:3a si n Ta 3 N 5 is not the limit for the Ta-N system. [32] Several TaN 2 polymorphs with P4/mbm, [33] pyrite Pa " 3 ÀÁ , [34] and P6 3 /mmc [35] crystal structures were considered in early theoretical studies. Recently,u sing ap article swarm optimization methodology Xing et al predicted that two thermodynamically stable TaN 2 polymorphs with C2/m and Cmce symmetries can be synthesized under pressures above 9a nd 65 GPa, respectively.…”

Section: Introductionmentioning

confidence: 99%

Stabilization of Polynitrogen Anions in Tantalum–Nitrogen Compounds at High Pressure

et al. 2021

View full text Add to dashboard Cite

The synthesis of polynitrogen compounds is of great importance due to their potential as high-energy-density materials (HEDM), but because of the intrinsic instability of these compounds,t heir synthesis and stabilization is af undamental challenge.P olymeric nitrogen units whichm ay be stabilized in compounds with metals at high pressure are now restricted to non-branched chains with an average NÀNb ond order of 1.25, limiting their HEDM performances.Herein, we demonstrate the synthesis of an ovel polynitrogen compound TaN 5 via ad irect reaction between tantalum and nitrogen in adiamond anvil cell at circa 100 GPa. TaN 5 is the first example of am aterial containing branched all-single-bonded nitrogen chains [N 5 5À ] 1 .A part from that we discover two novel TaN compounds:T aN 4 with finite N 4 4À chains and the incommensurately modulated compound TaN 2Àx ,which is recoverable at ambient conditions.

show abstract

Mechanical and metallic properties of tantalum nitrides from first-principles calculations

Cited by 57 publications

References 50 publications

Phase diagram, mechanical properties, and electronic structure of Nb–N compounds under pressure

Phase diagram, mechanical properties, and electronic structure of Nb–N compounds under pressure

Structural, mechanical and electronic properties of Rh2B and RhB2: first-principles calculations

Stabilization of Polynitrogen Anions in Tantalum–Nitrogen Compounds at High Pressure

Contact Info

Product

Resources

About