Design of Mg alloys: The effects of Li concentration on the structure and elastic properties in the Mg-Li binary system by first principles calculations

Pavlic, Olivia; Ibarra-Hernández, Wilfredo; Valencia-Jaime, Irais; Singh, Sobhit; Avendaño-Franco, Guillermo; Raabe, Dierk; Romero, Aldo H.

doi:10.1016/j.jallcom.2016.08.217

Cited by 48 publications

(24 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such a bipartite phonon dispersion was found in SnSe with the Pnma structure [57]. In a previous paper, we have found that the phonon band crossing helps to reduce the thermal conductivity in Li-Mg compounds [58].…”

Section: (Gete) 2 (Sb 2 Te 3 ) (Gst225)supporting

confidence: 54%

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B

View full text Add to dashboard Cite

We use ab initio density functional theory calculations to understand the electronic, dynamical, and thermoelectric behavior of layered crystalline phase-change materials. We perform calculations on the pseudobinary compounds (GeTe) x /(Sb 2 Te 3 ) (GST) with x = 1, 2, and 3. Since the stable configuration of these compounds remains somehow unsettled, we study one stacking configuration for GST124 (x = 1), three for GST225 (x = 2), and two for GST326 (x = 3). A supercell approach is used to check the dynamical stability of the systems while thermoelectric properties are obtained by solving the Boltzmann transport equation. We report that the most accepted stacking configuration of GST124, GST225, and GST326 have metallic character and for the case of x = 2 and 3, those are the ones with the lowest energy. However, we find the metallic of GST326 configuration to be dynamically unstable. In general, our values of the Seebeck coefficient and thermal conductivity for compounds with x = 1 and 2 agree very well with the available experimental data. The small differences that we observe with respect to experimental data are attributed to the disorder that is present experimentally and that we have not taken into account. We do not find a Dirac cone in the electronic band structure of GST225, contrarily to previous reports. We attribute this due to the theoretical strain induced by the choice of the pseudopotential.

show abstract

Section: (Gete) 2 (Sb 2 Te 3 ) (Gst225)supporting

confidence: 54%

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…Although the acoustic phonons mainly govern the heat transfer process, the optical phonons provide various scattering channels which could reduce the acoustic phonon life-times through acoustic-optic phonon scattering mechanisms. 94 A very low lattice thermal conductivity is expected in graphene/MoS 2 heterostructures along the vertical stacking direction due to the weak vdW bonding. The presence of multiple phonon band crossings in the phonon spectra (see Fig.…”

Section: Resultsmentioning

confidence: 99%

Structural, electronic, vibrational, and elastic properties of graphene/ MoS2 bilayer heterostructures

2018

Self Cite

View full text Add to dashboard Cite

Graphene/MoS2 van der Waals (vdW) heterostructures have promising technological applications due to their unique properties and functionalities. Many experimental and theoretical research groups across the globe have made outstanding contributions to benchmark the properties of graphene/MoS2 heterostructures. Even though some research groups have modeled the graphene/MoS2 heterostructures using first-principles calculations, there exists several discrepancies in the results from different theoretical research groups and the experimental findings. In the present work, we revisit this problem by means of first-principles calculations and address the existing discrepancies about the interlayer spacing between graphene and MoS2 monolayers in graphene/MoS2 heterostructures, and about the location of Dirac points near Fermi-level. We further investigate the electronic, mechanical and vibrational properties of the optimized graphene/MoS2 heterostructures created using 5×5/4×4 and 4×4/3×3 supercell geometries having different magnitudes of lattice mismatch. The effect of the varying interlayer spacing on the electronic properties of heterostructures is discussed. Our phonon calculations reveal that the interlayer shear and breathing phonon modes, which are very sensitive to the weak vdW interactions, play vital role in describing the thermal properties of the studied systems. The thermodynamic and elastic properties of heterostructures are further discussed. A systematic comparison between our results and the results reported from other research groups is presented.

show abstract

“…A way to measure the brittleness or ductility of a material comes from the ratio of the bulk modulus to the shear modulus, B/G ratio, with values above 1.7 giving ductile behavior. 58,59 Figures 2 (a-c) show the observed variation in the B, G, and E values as a function of Bi-concentration in Bi x Sb 1−x . Red (Blue) color represents the data points calculated with (without) inclusion of SOC.…”

Section: B Mechanical Propertiesmentioning

confidence: 99%

Elastic, mechanical, and thermodynamic properties of Bi-Sb binaries: Effect of spin-orbit coupling

et al. 2018

Self Cite

View full text Add to dashboard Cite

Using first principles calculations, we systematically study the elastic stiffness constants, mechanical properties, elastic wave velocities, Debye temperature, melting temperature, and specific heat of several thermodynamically stable crystal structures of BixSb1−x (0 < x < 1) binaries, which are of great interest due to their numerous inherent rich properties, such as thermoelectricity, thermomagnetic cooling, strong spin-orbit coupling (SOC) effects, and topological features in the electronic bandstructure. We analyze the bulk modulus (B), Young's modulus (E), shear modulus (G), B/G ratio, and Poisson's ratio (ν) as a function of the Bi concentration in BixSb1−x. The effect of SOC on above mentioned properties is further investigated. In general, we observe that the SOC effects cause elastic softening in most of the studied structures. Three monoclinic structures of Bi-Sb binaries are found to exhibit significantly large auxetic behavior due to the hinge-like geometric structure of bonds. The Debye temperature and the magnitude of the elastic wave velocities monotonically increase with increasing Sb-concentration. However, anomalies were observed at very low Sb-concentration. We also discuss the specific heat capacity versus temperature data for all studied binaries. Our theoretical results are in excellent agreement with the existing experimental and theoretical data. The comprehensive understanding of the material properties such as hardness, mechanical strength, melting temperature, propagation of the elastic waves, auxeticity, and heat capacity is vital for practical applications of the studied binaries.

show abstract

Design of Mg alloys: The effects of Li concentration on the structure and elastic properties in the Mg-Li binary system by first principles calculations

Cited by 48 publications

References 48 publications

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B

Structural, electronic, vibrational, and elastic properties of graphene/ MoS2 bilayer heterostructures

Elastic, mechanical, and thermodynamic properties of Bi-Sb binaries: Effect of spin-orbit coupling

Contact Info

Product

Resources

About

Design of Mg alloys: The effects of Li concentration on the structure and elastic properties in the Mg-Li binary system by first principles calculations

Cited by 48 publications

References 48 publications

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)Ibarra-Hernández1, Raty2 2018Phys. Rev. B

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)Ibarra-Hernández1, Raty2 2018Phys. Rev. B

Structural, electronic, vibrational, and elastic properties of graphene/ MoS2 bilayer heterostructures

Elastic, mechanical, and thermodynamic properties of Bi-Sb binaries: Effect of spin-orbit coupling

Contact Info

Product

Resources

About

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B

Ab initio density functional theory study of the electronic, dynamic, and thermoelectric properties of the crystalline pseudobinary chalcogenide (GeTe)x/(Sb2Te3)
Ibarra-Hernández
¹
,
Raty
²

2018
Phys. Rev. B