Cr concentration driving the structural, mechanical, and thermodynamic properties of Cr‐Al compounds from first‐principles calculations

Pan, Yong

doi:10.1002/qua.25943

Cited by 12 publications

(4 citation statements)

References 47 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The electronic properties of a semiconductor are estimated by the band structure and density of state. [66][67][68][69] To explore the role of N-vacancy on the electronic and optical properties, Figure 2 shows the calculated band structure of three bulk GaN with the N-vacancy. The previous works mainly focused on the electronic properties of the monolayer GaN.…”

Section: Resultsmentioning

confidence: 99%

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Pan¹

2021

Intl J of Energy Research

Self Cite

View full text Add to dashboard Cite

Gallium nitride (GaN) is a promising semiconductor material for the application of the high power electronic, optoelectronic, laser diodes, etc. The previous works have been focused on the electronic and optical properties of the monolayer GaN. However, the structural, electronic and optical properties of the bulk GaN are unclear. In particular, the role of N-vacancy on the electronic and optical properties of the bulk GaN is unknown. In this work, we apply first-principles calculations to study the influence of N-vacancy on the structural, electronic and optical properties of the bulk GaN. Three bulk GaN: hexagonal (P63/mc), cubic (F-43m) and cubic (Fm-3m) are considered. The result shows that the N-vacancy is thermodynamic stability in bulk GaN. The thermodynamic stability of the GaN with the N-vacancy is demonstrated by the change of Ga N bond. Three GaN show the semiconductor feature because of the role of N-2p state. The calculated band gap of GaN with the P63mc, F-43m and Fm-3m is 1.651, 1.489 and 0.450 eV. However, the N-vacancy enhances the electronic jump of GaN because the N-vacancy induces the move of the position of Fermi level to the region of the conduction band. The metallic behavior of GaN with the N-vacancy is demonstrated by the dielectric function diagram. In particular, the N-vacancy gives rise to the visible light region optical adsorption compared to the corresponding bulk GaN.

show abstract

Section: Resultsmentioning

confidence: 99%

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Pan¹

2021

Intl J of Energy Research

Self Cite

View full text Add to dashboard Cite

show abstract

“…The mechanical properties play an important role in high-temperature structural material [53][54][55]. So it must be studied their elastic modulus [56].…”

Section: Model and Calculated Methodsmentioning

confidence: 99%

Prediction the structure, mechanical properties and melting point ofD8_m‐Mo₅SiB₂andCmcm‐Mo₅SiB₂

Pan

2021

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

Mo 5 SiB 2 is an ideal candidate for high temperature material. Although the D8 l -Mo 5 SiB 2 has been published, the other phases and the related properties of Mo 5 SiB 2 are still unclear. Here, two possible Mo 5 SiB 2 phases (D8 m -Mo 5 SiB 2 and Cmcm-Mo 5 SiB 2 ) are predicted by using the first principles method. The structural stability, mechanical properties, melting point and electronic structure of Mo 5 SiB 2 are studied. The results show that the D8 m -Mo 5 SiB 2 and Cmcm-Mo 5 SiB 2 are thermodynamically and dynamically stables. The calculated bulk elastic modulus, shear modulus and Young's modulus of the Cmcm-Mo 5 SiB 2 are close to D8 l -Mo 5 SiB 2 . In addition, the predicted Cmcm-Mo 5 SiB 2 has high melting point (2518.5 C) compared to the D8 l -Mo 5 SiB 2 and D8 m -Mo 5 SiB 2 . In particular, the predicted D8 m -Mo 5 SiB 2 exhibits better plasticity than the D8 l -Mo 5 SiB 2 . The calculated density of states and Mulliken overlap population shows that the D8 m -Mo 5 SiB 2 and Cmcm-Mo 5 SiB 2 all exhibit metallic behavior. The metallic behavior mainly depends on the electronic interaction between Mo atom and B atom near Fermi level. Furthermore, the bond length of Mo-B bond in the D8 m -Mo 5 SiB 2 is longer than the other two structures, which may be the reason why the ductility of the former is better than the latter. K E Y W O R D S first-principles method, mechanical properties, melting point, Mo 5 SiB 2 , structural prediction 1 | INTRODUCTION The search for excellent high-temperature materials is also a big challenge for the development of modern industrial [1-8]. Mo 5 SiB 2 ternary silicide is regarded as an ideal candidate material for aero-engine turbine blades and industrial gas turbine hot-end components because of its high melting point, good mechanical properties and good oxidation resistance [9-15]. In 1957, Nowotny et al. have been studied the phase diagram of Mo-Si-B ternary silicide by using the phase diagram method. The Mo-Si-B ternary phase is discovered for the first time [16]. In 1958, Aronsson discovered by powder photography that this Mo-Si-B ternary phase has a body-centered tetragonal structure (D8 l ) similar to Cr 5 B 3 , and gave its lattice parameters a = b = 6.02 Å, c = 11.07 Å [17]. As we all know, the good oxidation resistance, excellent mechanical properties and good ductility are necessary conditions for high temperature materials [18][19][20][21][22][23][24]. In terms of mechanical properties, Mo 5 SiB 2 ternary silicide has high single crystal elastic constants at room temperature (RT): C 11 = 480 GPa, C 33 = 415 GPa, C 12 = 166 GPa, C 13 = 197GPa, C 44 = 174GPa and C 66 = 143 GPa [25]. Furthermore, the bulk elastic modulus, shear modulus and Young's modulus of Mo 5 SiB 2 are 271GPa, 152GPa and 385GPa, which indicate that Mo 5 SiB 2 is an extremely high temperature material [26]. In addition, it is found that there are numerous dislocations in the Mo 5 SiB 2 crystal, which will benefit its ductility [27,28]. In terms of oxidation resistance, Akinc et al. have been ...

show abstract

“…The dynamic stability of the predicted structure is measured by the phonon frequency and PhDOS. [67] The imaginary phonon and negative frequencies indicate the dynamically instability for a solid, and vice versa. To explore the structural stability, Figure 2 displays the calculated phonon dispersion curves and PhDOS of five TMZr compounds.…”

Section: Structural Stabilitymentioning

confidence: 99%

The structural, mechanical, and thermodynamic properties of B2‐type TMZr (TM = Ru, Mo, Rh, Os, and Re) compounds from first‐principles calculations

Pan

2019

Int J of Quantum Chemistry

Self Cite

View full text Add to dashboard Cite

The B2‐type cubic Zr‐based compounds are attractive advanced high‐temperature materials because of the strong and symmetrical bonds. However, the mechanical and thermodynamic properties of the B2‐type cubic Zr‐based compounds are not well understood. Here, we use the first‐principles calculations to investigate the structural, elastic modulus, ductility, and thermodynamic properties of TMZr (TM = Ru, Mo, Rh, Os, and Re) compounds. Two novel TMZr compounds, MoZr and ReZr, are first predicted by using the phonon dispersion and formation enthalpy, respectively. The results show that the B2‐type TMZr compounds not only exhibit high elastic modulus but also show better ductility due to the symmetrical TM‐Zr metallic bonds. In particular, the calculated elastic modulus of OsZr is larger than that of the other four TMZr compounds, indicating that the OsZr shows the strongest deformation resistance in five TMZr compounds. The calculated Θ D of RuZr is 328 K, which is larger than that of the other four TMZr compounds. The calculated phonon density of state shows that the high‐temperature thermodynamic properties of TMZr derive from the vibration of Zr atom. Therefore, our work predicts that the B2‐type OsZr is an attractive high‐temperature structural material.

show abstract

Cr concentration driving the structural, mechanical, and thermodynamic properties of Cr‐Al compounds from first‐principles calculations

Cited by 12 publications

References 47 publications

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Prediction the structure, mechanical properties and melting point ofD8_m‐Mo₅SiB₂andCmcm‐Mo₅SiB₂

The structural, mechanical, and thermodynamic properties of B2‐type TMZr (TM = Ru, Mo, Rh, Os, and Re) compounds from first‐principles calculations

Contact Info

Product

Resources

About

Cr concentration driving the structural, mechanical, and thermodynamic properties of Cr‐Al compounds from first‐principles calculations

Cited by 12 publications

References 47 publications

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Influence of N‐vacancy on the electronic and optical properties of bulk GaN from first‐principles investigations

Prediction the structure, mechanical properties and melting point ofD8m‐Mo5SiB2andCmcm‐Mo5SiB2

The structural, mechanical, and thermodynamic properties of B2‐type TMZr (TM = Ru, Mo, Rh, Os, and Re) compounds from first‐principles calculations

Contact Info

Product

Resources

About

Prediction the structure, mechanical properties and melting point ofD8_m‐Mo₅SiB₂andCmcm‐Mo₅SiB₂