First-principles study of the structural, electronic and elastic properties of W5Si3

Tao, Xiaoma; Jund, Philippe; Colinet, C.; Tedenac, Jean‐Claude

doi:10.1016/j.intermet.2009.11.008

Cited by 44 publications

(13 citation statements)

References 32 publications

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“…1 one can see that the equilibrium structure of Ta 5 Si 3 is the D8 l structure while the D8 m structure is the equilibrium structure of W 5 Si 3 both having the body centered tetragonal structure with space group I4/mcm. These results are in agreement with the available experimental data as well as the other simulated structural data [3] and [4].…”

Section: Resultssupporting

confidence: 92%

“…Three crystallographic structures have been considered: the W 5 Si 3 -prototype structure (D8 m ), the Cr 5 B 3 -prototype structure (D8 l ) and the Mn 5 Si 3 -prototype structure (D8 8 ). The calculated lattice constants and several elastic constants can be found in ref [3] and [4] and are not recalled here but in Fig. 1 one can see that the equilibrium structure of Ta 5 Si 3 is the D8 l structure while the D8 m structure is the equilibrium structure of W 5 Si 3 both having the body centered tetragonal structure with space group I4/mcm.…”

Section: Resultsmentioning

confidence: 99%

“…This shows that the stability issues are also of fundamental interest in the search of new materials for high temperature applications. It is worth noting that no study has focused on the potential for thermoelectricity of transition metal silicides with a low Si content such as M 5 Si 3 (M=Ta,W), which we have recently begun to study [3,4]. Thus, the aim of the present study is to determine the equilibrium structure of Ta 5 Si 3 and W 5 Si 3 which are stable above 2000C [3,4] and to determine their thermopower using Mott's law.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Stability and Thermoelectric Properties of Transition Metal Silicides from First Principles Calculations

Jund¹,

Tao²,

Viennois³

et al. 2011

Energy Technology 2011

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We report an ab-initio study of the stability and electronic properties of transition metal silicides in order to study their potential for high temperature thermoelectric applications. We focus on the family M 5 Si 3 (M = Ta, W) which is stable up to about 2000 °C. We first investigate the structural stability of the two compounds and then determine the thermopower of the equilibrium structure using the electronic density of states and Mott's law. We find that W 5 Si 3 has a relatively large thermopower but probably not sufficient enough for thermoelectric applications.

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Section: Resultssupporting

confidence: 92%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Stability and Thermoelectric Properties of Transition Metal Silicides from First Principles Calculations

Jund¹,

Tao²,

Viennois³

et al. 2011

Energy Technology 2011

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“…To further reveal the charge transfer and the chemical bonding properties of both non-doped and doped Ta 5 Si 3 , the difference in bonding charge density for the three compounds was investigated. The bonding charge density, also called the deformation charge density, is defined as the difference between the self-consistent charge density of the interacting atoms in the crystal and a reference charge density constructed from the superposition of the non-interacting atomic charge density at the lattice sites [47]. The distribution of the bonding charge densities in the (001) plane along the a-and b-axis for non-doped and doped Ta 5 Si 3 is given in Figures 8 and 9 where the red region denotes a high charge density and the blue region denotes a relatively low charge density.…”

Section: Electronic Structure and Population Analysismentioning

confidence: 99%

The Effects of Al and Ti Additions on the Structural Stability, Mechanical and Electronic Properties of D8m-Structured Ta5Si3

Liu

Cheng

et al. 2016

Metals

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Abstract:In the present study, the influence of substitutional elements (Ti and Al) on the structural stability, mechanical properties, electronic properties and Debye temperature of Ta 5 Si 3 with a D8 m structure were investigated by first principle calculations. The Ta 5 Si 3 alloyed with Ti and Al shows negative values of formation enthalpies, indicating that these compounds are energetically stable. Based on the values of formation enthalpies, Ti exhibits a preferential occupying the Ta 4b site and Al has a strong site preference for the Si 8h site. From the values of the bulk modulus (B), shear modulus (G) and Young's modulus (E), we determined that both Ti and Al additions decrease both the shear deformation resistance and the elastic stiffness of D8 m structured Ta 5 Si 3 . Using the shear modulus/bulk modulus ratio (G/B), Poisson's ratio (υ) and Cauchy's pressure, the effect of Ti and Al additions on the ductility of D8 m -structured Ta 5 Si 3 are explored. The results show that Ti and Al additions reduce the hardness, resulting in solid solution softening, but improve the ductility of D8 m -structured Ta 5 Si 3 . The electronic calculations reveal that Ti and Al additions change hybridization between Ta-Si and Si-Si atoms for the binary D8 m -structured Ta 5 Si 3 . The new Ta-Al bond is weaker than the Ta-Si covalent bonds, reducing the covalent property of bonding in D8 m -structured Ta 5 Si 3 , while the new strong Ti 4b -Ti 4b anti-bonding enhances the metallic behavior of the binary D8 m -structured Ta 5 Si 3 . The change in the nature of bonding can well explain the improved ductility of D8 m -structured Ta 5 Si 3 doped by Ti and Al. Moreover, the Debye temperatures, Θ D , of D8 m -structured Ta 5 Si 3 alloying with Ti and Al are decreased as compared to the binary Ta 5 Si 3 .

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“…[14][15][16][17] According to the Si concentrations, transition metal silicides can be divided into TM 5 Si 3 , TMSi 2 , and TM 3 Si. [18][19][20][21] Among them, TM 5 Si 3 silicide has been widely studied due to the high melting point, excellent elastic properties, and high temperature creep resistance. [22][23][24][25] For example, the melting point of Ta 5 Si 3 is up to 2550 • C, which is much higher than the Ni-based superalloys.…”

Section: Introductionmentioning

confidence: 99%

First‐principles investigation of solution mechanism of C in TM‐Si‐C matrix as the potential high‐temperature ceramics

Pan

2021

J Am Ceram Soc.

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Although the TM-Si-C ternary compounds are promising advanced ceramics, the solution mechanism of C element in TM-Si matrix is entirely unclear. In particular, the influence of C on the mechanical properties of TM-Si matrix is no clear. To solve the problem, we apply the first-principles calculations to study the occupied mechanism of C in TM 5 Si 3 silicides. In addition, the influence of C element on the mechanical properties of TM 5 Si 3 is further studied. Here, two typical TM 5 Si 3 phases: D8 l -Ta 5 Si 3 and D8 m -Mo 5 Si 3 are considered. For C-doping, six C interstitial sites,

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First-principles study of the structural, electronic and elastic properties of W5Si3

Cited by 44 publications

References 32 publications

Stability and Thermoelectric Properties of Transition Metal Silicides from First Principles Calculations

Stability and Thermoelectric Properties of Transition Metal Silicides from First Principles Calculations

The Effects of Al and Ti Additions on the Structural Stability, Mechanical and Electronic Properties of D8m-Structured Ta5Si3

First‐principles investigation of solution mechanism of C in TM‐Si‐C matrix as the potential high‐temperature ceramics

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