Physical properties of the recently discovered Zr2(Al1−x Bi x )C MAX phases

Hadi, M. A.; Вовк, Р. В.; Chroneos, Alexander

doi:10.1007/s10854-016-5338-z

Cited by 83 publications

(49 citation statements)

References 47 publications

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“…The optical properties are usually calculated from the complex dielectric function, where ε 1 is the real part of dielectric function derived from the Kramer-Kronig relations and ε 2 is the imaginary part of the dielectric function which is computed from the momentum matrix elements between the occupied and unoccupied wave functions. The equations for calculations of different optical functions can be found elsewhere [47,48].…”

Section: Optical Propertiesmentioning

confidence: 99%

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Barua

Hossain

Ali

et al. 2019

Journal of Alloys and Compounds

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In the present study, the effects of transition metals on structural, electronic, elastic, optical and thermodynamic properties of M 2 BC (M = V, Nb, Mo and Ta) have been investigated using the density functional theory based first-principles method. The electronic band structures along with Fermi surface, elastic anisotropy, Vickers hardness, analysis of Mulliken populations, optical and thermodynamic properties are studied for the first time. The optimized unit cell parameters are compared with available theoretical and experimental results and a reasonable agreement is recorded. The mechanical stability of these compounds is confirmed by the calculations of single crystals elastic constants using the Born criteria conditions. The compounds herein exhibit metallic conductivity where major contribution comes from the d-orbital electrons. The total density of states at E F are found to be 9.15, 6.77, 6.37 and 5.83 states/eV/unit cells for M 2 BC (M = V, Nb, Mo and Ta) compounds, respectively. The hardness values of 10.71, 12.44, 8.52 and 16.80 GPa are noted for the M 2 BC (M = V, Nb, Mo and Ta) compounds, respectively. The value of bulk modulus, B is found to increase in the sequence of B (V 2 BC) < B (Nb 2 BC) < B (Ta 2 BC) < B (Mo 2 BC), indicating Mo 2 BC is highly stiff among the compounds under study. The Mo 2 BC and Ta 2 BC compounds might be considered as potential candidates for cutting and forming tools due to the moderately ductile and highly stiff behavior compared to other benchmark hard coating materials such as TiN, TiAlN, Ti 0.5 Al 0.5 N and c-BN. Ta 2 BC compound could also be a promising thermal barrier coating (TBC) material due to its low thermal conductivity, Debye temperature and damage tolerant behavior. Different anisotropy calculations (shear anisotropic factors, percentage anisotropy factors and universal anisotropic index) confirm that the compounds are structurally anisotropic in nature. The bond between C-V/Nb/Mo/Ta shows that the degree of covalency is higher compared to B-V/Nb/Mo/Ta bond. Various optical functions (such as dielectric constants, refractive index, photo-conductivity, absorption, loss function and reflectivity) are calculated and discussed using established formalism. The amount of reflectivity is always more than 50% with no significant change in the near infrared, visible and near ultraviolet region (upto ~ 6 eV), this result makes the compounds promising coating materials to diminish solar heating.

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Section: Optical Propertiesmentioning

confidence: 99%

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Barua

Hossain

Ali

et al. 2019

Journal of Alloys and Compounds

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“…The structure consists of the stacking of n “ceramic” layer(s) inserted by an A “metallic” layer . A good number of MAX phase compounds have then been synthesized and the physical properties investigated . For example, the M 2 AX phases with M = (Ti, V, Cr, Nb, Ta, Zr, Hf); A = (Al, S, Sn, As, In, Ga), and X = (N, C) have been studied both experimentally and theoretically because of their attractive properties as stated earlier .…”

Section: Introductionmentioning

confidence: 99%

Predicted MAX Phase Sc₂InC: Dynamical Stability, Vibrational and Optical Properties

Chowdhury

Ali

Hossain

et al. 2017

Physica Status Solidi (b)

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First principles pseudopotential calculations have been performed for the first time to investigate the phonon dispersion, thermodynamic and optical properties including charge density, Fermi surface, Mulliken population analysis, theoretical Vickers hardness of predicted MAX phase Sc2InC. We revisited the structural, elastic, and electronic properties of the compound which assessed the reliability of our calculations. The analysis of the elastic constants and the phonon dispersion along with phonon density of states indicates the mechanical stability and dynamical stability of the Sc2InC. The Helmholtz free energy, internal energy, entropy specific heat capacity, and Debye temperature have also been calculated. Mulliken population analysis indicates the existence of prominent covalency in chemical bonding of Sc2InC. The electronic charge density mapping shows a combination of ionic, covalent and metallic bonding in the compound. The Fermi surface is comprised due to the low‐dispersive Sc 3d and C 2p states from the [ScC] blocks. The phase is expected to be a soft material and easily machinable due to its low Vickers hardness value. Furthermore, the analysis of various optical properties suggests that the nanolaminate Sc2InC is a promising candidate for optoelectronic devices in the visible and ultraviolet energy regions and as a coating material to avoid solar heating.

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“…The variation in bond length with the applied pressure has a close contact with the bonding characteristics. The 3.282 (LDA) 3.3 10 3.3174 32 14.405 (LDA) 14.6 10 14.6304 32 3.3294 10 3.334 33 14.556 10 14.600 33 3.319 34 14.604 34 3.3183 35 14.6178 35 3.327 36 The available experimental data on Hf-Al-C and Ti-Al-C system are listed for comparison.…”

Section: Structures and Bonding Of Zr-al-c Systemsmentioning

confidence: 99%

Elastic, mechanical, electronic, and defective properties of Zr–Al–C nanolaminates from first principles

et al. 2017

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By means of first principles calculations, Zr–Al–C nanolaminates have been studied in the aspects of chemical bonding, elastic properties, mechanical properties, electronic structures, and vacancy stabilities. Although the investigated Zr–Al–C nanolaminates show crystallographic similarities, their predicated properties are very different. For (ZrC)nAl3C2 (n = 2, 3, 4), the Zr–C bond adjacent to the Al–C slab with the C atom intercalated in the Zr layers is the strongest, but the one with the C atom intercalated between the Zr layer and Al layer is the weakest. In contrast, the situation for (ZrC)nAl4C3 (n = 2, 3) is just the opposite. For Zr–Al–C nanolaminates, the calculated bulk, shear and Young's modulus increase in the sequence of Zr2AlC < Zr3AlC2 < Zr2Al4C5 < Zr3Al4C6 < Zr2Al3C4 < Zr3Al3C5 < Zr4Al3C6. The (ZrC)nAl3C2 (n = 2, 3, 4) series exhibit the most outstanding elastic properties. In the presence of the external pressure, the bulk and shear moduli exhibit a linear response to the pressure, except for Zr2AlC and Zr3AlC2, both of which belong to the so‐called MAX phases. The two materials also exhibit very distinct properties in the strain‐stress relationship, electronic structures and vacancy stabilities. As the intercalated Al layers increase, the formation energy of VZr and VAl increases, while the formation energy of VC decreases.

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Physical properties of the recently discovered Zr2(Al1−x Bi x )C MAX phases

Abstract: This document is the author's post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version may remain and you are advised to consult the published version if you wish to cite from it.

Cited by 83 publications

References 47 publications

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Predicted MAX Phase Sc₂InC: Dynamical Stability, Vibrational and Optical Properties

Elastic, mechanical, electronic, and defective properties of Zr–Al–C nanolaminates from first principles

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Physical properties of the recently discovered Zr2(Al1−x Bi x )C MAX phases

Abstract: This document is the author's post-print version, incorporating any revisions agreed during the peer-review process. Some differences between the published version and this version may remain and you are advised to consult the published version if you wish to cite from it.

Cited by 83 publications

References 47 publications

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Predicted MAX Phase Sc2InC: Dynamical Stability, Vibrational and Optical Properties

Elastic, mechanical, electronic, and defective properties of Zr–Al–C nanolaminates from first principles

Contact Info

Product

Resources

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Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Effects of transition metals on physical properties of M2BC (M = V, Nb, Mo and Ta): A DFT calculation

Predicted MAX Phase Sc₂InC: Dynamical Stability, Vibrational and Optical Properties