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Alexander Chroneos - One of the best experts on this subject based on the ideXlab platform.
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Elastic behaviour and radiation tolerance in Nb-based 211 MAX Phases
Materials Today Communications, 2020Co-Authors: M A Hadi, Alexander Chroneos, Stavros Christopoulos, S. H. Naqib, A. K. M. A. IslamAbstract:Abstract MAX phase carbides are a set of materials that have attracted the research and industrial interest due to their unique combination of metallic and ceramic properties. In recent experimental studies it was determined that Nb-based MAX Phases have good mechanical and thermal properties. In the present systematic density functional theory study we examine the elastic behaviour and radiation tolerance of a range of Nb2AC (A = Al, Ga, Ge, In, Sn, As, P, and S) MAX Phases. It is found that the Nb-based 211 MAX Phases studied here are mechanically stable and elastically anisotropic. Elastically, Nb2GeC possesses the highest level of anisotropy and Nb2InC, the lowest. The cross-slip pinning process is enhanced in Nb2GeC that is considerably reduced in Nb2InC. Nb2GeC, Nb2SnC, and Nb2SC are ductile, whereas the other Nb-based MAX Phases considered here are brittle in nature. In particular, Nb2GeC is highly ductile and Nb2AlC is more brittle. Nb2PC and Nb2SnC are respectively, more stiff and flexible under tension or compression. Nb2SnC has the best thermal shock resistance among the Nb-based MAX phase carbides studied here. Regarding the radiation tolerance of these MAX Phases it is anticipated that Nb2SnC will be the most resistant to radiation.
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Electronic structures, bonding natures and defect processes in Sn-based 211 MAX Phases
Computational Materials Science, 2019Co-Authors: M A Hadi, Nikolaos Kelaidis, Alexander Chroneos, S. H. Naqib, A. K. M. A. IslamAbstract:Abstract The electronic structure, bonding natures, and defect processes of the new superconducting MAX phase Lu2SnC are investigated by using density functional theory, and are compared to other existing M2SnC Phases. The formation of M2SnC MAX Phases is exothermic and these compounds are intrinsically stable in agreement with experiment. The finite value of DOS, in addition to the d-resonance at the vicinity of the Fermi level, indicates a metallic nature and conductivity of M2SnC MAX Phases. The strength of the covalent M–C bond is higher than that of the covalent M–Sn bond. The calculated effective valence charge also indicates the dominance of covalency in the chemical bonding in the studied compounds. The charge transfer in M2SnC Phases indicates the ionic nature of their chemical bonds. The ionic character of their chemical bonds can also be understood from the spherical nature of charge distribution in their contour maps of electron charge density. Therefore, the overall bonding nature in the studied M2SnC MAX Phases is a combination of metallic, covalent, and, ionic. The bond length is directly proportional to the crystal radius, while bond covalency is inversely proportional to the crystal radius. Additionally, the Fermi surface topology is also investigated. Considering the intrinsic defect processes it is calculated that Nb2SnC is the material that is predicted to have better radiation tolerance.
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intrinsic defect processes and elastic properties of ti3ac2 a al si ga ge in sn MAX Phases
Journal of Applied Physics, 2018Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Petros-panagis Filippatos, M A Hadi, M E Fitzpatrick, Alexander ChroneosAbstract:Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3A...
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intrinsic defect processes and elastic properties of ti3ac2 a al si ga ge in sn MAX Phases
Journal of Applied Physics, 2018Co-Authors: Stavros Christopoulos, Nikolaos Kelaidis, Petros-panagis Filippatos, M A Hadi, M E Fitzpatrick, Alexander ChroneosAbstract:Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3AlC2 is nearly isotropic.Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3A...
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defect processes of m3alc2 m v zr ta ti MAX Phases
Solid State Communications, 2017Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Alexander ChroneosAbstract:Abstract The interest on the M n+1 AX n Phases (M = early transition metal; A = group 13–16 element and X = C and/or N) stems from their combination of advantageous metallic and ceramic properties. Aluminium containing 312 MAX Phases in particular are deemed to enhance high-temperature oxidation resistance. In the present study, we use density functional theory calculations to study the intrinsic defect processes of M 3 AlC 2 MAX Phases (M = V, Zr, Ta, Ti). The calculations reveal that Ti 3 AlC 2 is the more radiation tolerant 312 MAX phase considered here. In Ti 3 AlC 2 the carbon Frenkel reaction is the lowest energy defect process with 3.17 eV. Results are discussed in view of recent experimental and theoretical results of related systems.
Michel W. Barsoum - One of the best experts on this subject based on the ideXlab platform.
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On the Chemical Diversity of the MAX Phases
Trends in Chemistry, 2019Co-Authors: Maxim Sokol, Sankalp Kota, Varun Natu, Michel W. BarsoumAbstract:The M n+1 AX n , or MAX, Phases are nanolayered, hexagonal, machinable, early transition-metal carbides and nitrides, where n = 1, 2, or 3, M is an early transition metal, A is an A-group element (mostly groups 13 and 14), and X is C and/or N. These Phases are characterized by a unique combination of both metallic and ceramic properties. The fact that these Phases are precursors for MXenes and the dramatic increase in interest in the latter for a large host of applications render the former even more valuable. Herein we describe the structure of most, if not all, MAX Phases known to date. This review covers ≈155 MAX compositions. Currently, 16 A elements and 14 M elements have been incorporated in these Phases. The recent discovery of both quaternary in- and out-of-plane ordered MAX Phases opens the door to the discovery of many more. The chemical diversity of the MAX Phases holds the key to eventually optimizing properties for prospective applications. Since many of the newer quaternary (and higher)Phases have yet to be characterized, much work remains to be done.
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Crystallographic evolution of MAX Phases in proton irradiating environments
Journal of Nuclear Materials, 2018Co-Authors: Joseph Ward, Matthew Topping, Simon C. Middleburgh, Alistair Garner, David Stewart, Michael Preuss, Michel W. Barsoum, Philipp FrankelAbstract:This work represents the first use of proton irradiation to simulate in-core radiation damage in Ti3SiC2 and Ti3AlC2 MAX Phases. Irradiation experiments were performed to 0.1 dpa at 350 °C, with a damage rate of 4.57 × 10−6 dpa s−1. The MAX Phases displayed significant dimensional instabilities at the crystal level during irradiation leading to large anisotropic changes in lattice parameter, even at low damage levels. The instabilities were accompanied by a decomposition of the Ti-based MAX Phases to their binary constituents, TiC. Experimentally observed changes in lattice parameter have been correlated with density functional theory modelling. The most energetically favourable and/or most difficult to recombine defects considered were an M-A antisite ({MA:AM}), and carbon Frenkel ({VC:Ci}). It is proposed that antisite defects, {MA:AM}, are the main contributor to the observed changes in lattice parameter. The proposed mechanism reported in this work potentially enables to design MAX phase compositions, which do not favour antisite defect accumulation. In addition, comparison between the experimental results and theoretical calculations shows that a greater amount of residual damage remains in Ti3AlC2 when compared to Ti3SiC2 after the same irradiation treatment.
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Corrosion performance of Ti3SiC2, Ti3AlC2, Ti2AlC and Cr2AlC MAX Phases in simulated primary water conditions
Corrosion Science, 2018Co-Authors: Joseph Ward, S Holdsworth, Eric Prestat, David Bowden, David Stewart, Michael Preuss, Michel W. Barsoum, Philipp FrankelAbstract:The response of Ti3SiC2, Ti3AlC2, Ti2AlC and Cr2AlC MAX Phases under simulated primary water has been explored for the first time. Samples were tested for 28 days in 300 °C water with the addition of 2 ppm LiOH. The Ti-based MAX Phases formed oxides of TiO and TiFeO3. X-ray diffraction and scanning electron microscopy showed no evidence of a passive Al or Si-based layer forming during testing. A-layer dissolution was observed to cause delamination of the layered structure. In contrast, Cr2AlC showed little change during autoclave testing, suggesting that a thin passivating chromia layer was formed.
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magnetotransport in the MAX Phases and their 2d derivatives mxenes
Materials research letters, 2017Co-Authors: Thierry Ouisse, Michel W. BarsoumAbstract:ABSTRACTHerein, we critically assess magnetotransport in the MAX Phases and their 2D derivatives, MXenes. For some MAX Phases, a simple, 2D hexagonal metal model describes weak-field magnetotransport of their nearly free electrons reasonably well. For others, experimental and/or theoretical Fermi surfaces need to be mapped—a crucial task required for true understanding. Even less is known about MXenes. The density of apparent mobile carriers in Ti3C2Tx—assuming a single-band model—is ≈1 × 1014 cm−2 (1028 cm−3), which justifies it being sometimes described as a 2D metal. Much work is needed before a clearer picture emerges.Impact statement Magnetotransport in the MAX Phases and their 2D derivatives MXene are critically reviewed for the first time. For some, a 2D hexagonal metal can explain magnetotransport; in others not.
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magnetotransport in the MAX Phases and their 2d derivatives mxenes
Materials research letters, 2017Co-Authors: Thierry Ouisse, Michel W. BarsoumAbstract:ABSTRACTHerein, we critically assess magnetotransport in the MAX Phases and their 2D derivatives, MXenes. For some MAX Phases, a simple, 2D hexagonal metal model describes weak-field magnetotransport of their nearly free electrons reasonably well. For others, experimental and/or theoretical Fermi surfaces need to be mapped—a crucial task required for true understanding. Even less is known about MXenes. The density of apparent mobile carriers in Ti3C2Tx—assuming a single-band model—is ≈1 × 1014 cm−2 (1028 cm−3), which justifies it being sometimes described as a 2D metal. Much work is needed before a clearer picture emerges.Impact statement Magnetotransport in the MAX Phases and their 2D derivatives MXene are critically reviewed for the first time. For some, a 2D hexagonal metal can explain magnetotransport; in others not.
Stavros-richard G. Christopoulos - One of the best experts on this subject based on the ideXlab platform.
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intrinsic defect processes and elastic properties of ti3ac2 a al si ga ge in sn MAX Phases
Journal of Applied Physics, 2018Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Petros-panagis Filippatos, M A Hadi, M E Fitzpatrick, Alexander ChroneosAbstract:Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3A...
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defect processes of m3alc2 m v zr ta ti MAX Phases
Solid State Communications, 2017Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Alexander ChroneosAbstract:Abstract The interest on the M n+1 AX n Phases (M = early transition metal; A = group 13–16 element and X = C and/or N) stems from their combination of advantageous metallic and ceramic properties. Aluminium containing 312 MAX Phases in particular are deemed to enhance high-temperature oxidation resistance. In the present study, we use density functional theory calculations to study the intrinsic defect processes of M 3 AlC 2 MAX Phases (M = V, Zr, Ta, Ti). The calculations reveal that Ti 3 AlC 2 is the more radiation tolerant 312 MAX phase considered here. In Ti 3 AlC 2 the carbon Frenkel reaction is the lowest energy defect process with 3.17 eV. Results are discussed in view of recent experimental and theoretical results of related systems.
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experimental synthesis and density functional theory investigation of radiation tolerance of zr3 al1 xsix c2 MAX Phases
Journal of the American Ceramic Society, 2017Co-Authors: Eugenio Zapatasolvas, Denis Horlait, David C. Parfitt, Stavros-richard G. Christopoulos, Alexander Chroneos, M E Fitzpatrick, Na Ni, W E LeeAbstract:Synthesis, characterization and density functional theory calculations have been combined to examine the formation of the Zr3(Al1–xSix)C2 quaternary MAX Phases and the intrinsic defect processes in Zr3AlC2 and Zr3SiC2. The MAX phase family is extended by demonstrating that Zr3(Al1–xSix)C2, and particularly compositions with x≈0.1, can be formed leading here to a yield of 59 wt%. It has been found that Zr3AlC2 - and by extension Zr3(Al1–xSix)C2 - formation rates benefit from the presence of traces of Si in the reactant mix, presumably through the in situ formation of ZrySiz phase(s) acting as a nucleation substrate for the MAX phase. To investigate the radiation tolerance of Zr3(Al1–xSix)C2, we have also considered the intrinsic defect properties of the end-members. A-element Frenkel reaction for both Zr3AlC2 (1.71 eV) and Zr3SiC2 (1.41 eV) Phases are the lowest energy defect reactions. For comparison we consider the defect processes in Ti3AlC2 and Ti3SiC2 Phases. It is concluded that Zr3AlC2 and Ti3AlC2 MAX Phases are more radiation tolerant than Zr3SiC2 and Ti3SiC2, respectively. Their applicability as cladding materials for nuclear fuel is discussed.
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Defect processes of M3AlC2 (M = V, Zr, Ta, Ti) MAX Phases
Solid State Communications, 2017Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Alexander ChroneosAbstract:The interest on the Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C and/or N) stems from their combination of advantageous metallic and ceramic properties. Aluminium containing 312 MAX Phases in particular are deemed to enhance high-temperature oxidation resistance. In the present study, we use density functional theory calculations to study the intrinsic defect processes of M3AlC2 MAX Phases (M = V, Zr, Ta, Ti). The calculations reveal that Ti3AlC2 is the more radiation tolerant 312 MAX phase considered here. In Ti3AlC2 the carbon Frenkel reaction is the lowest energy defect process with 3.17 eV. Results are discussed in view of recent experimental and theoretical results of related systems.
Denis Horlait - One of the best experts on this subject based on the ideXlab platform.
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synthesis and physical properties of zr1 x tix 3alc2 MAX Phases
Journal of the American Ceramic Society, 2017Co-Authors: Eugenio Zapatasolvas, Denis Horlait, David C. Parfitt, Axel Thibaud, Mohammad A. Hadi, Alexander Chroneos, W E LeeAbstract:MAX phase solid solutions physical and mechanical properties may be tuned via changes in composition, giving them a range of possible technical applications. In the present study, we extend the MAX phase family by synthesizing (Zr1−xTix)3AlC2 quaternary MAX Phases and investigating their mechanical properties using density functional theory (DFT). The experimentally determined lattice parameters are in good agreement with the lattice parameters derived by DFT and deviate <0.5% from Vegard's law. Ti3AlC2 has a higher Vickers hardness as compared to Zr3AlC2, in agreement with the available experimental data.
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Synthesis and physical properties of (Zr1−x,Tix)3AlC2 MAX Phases
Journal of the American Ceramic Society, 2017Co-Authors: Eugenio Zapata-solvas, Denis Horlait, David C. Parfitt, Axel Thibaud, Mohammad A. Hadi, Alexander ChroneosAbstract:MAX phase solid solutions physical and mechanical properties may be tuned via changes in composition, giving them a range of possible technical applications. In the present study, we extend the MAX phase family by synthesizing (Zr1−xTix)3AlC2 quaternary MAX Phases and investigating their mechanical properties using density functional theory (DFT). The experimentally determined lattice parameters are in good agreement with the lattice parameters derived by DFT and deviate
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experimental synthesis and density functional theory investigation of radiation tolerance of zr3 al1 xsix c2 MAX Phases
Journal of the American Ceramic Society, 2017Co-Authors: Eugenio Zapatasolvas, Denis Horlait, David C. Parfitt, Stavros-richard G. Christopoulos, Alexander Chroneos, M E Fitzpatrick, Na Ni, W E LeeAbstract:Synthesis, characterization and density functional theory calculations have been combined to examine the formation of the Zr3(Al1–xSix)C2 quaternary MAX Phases and the intrinsic defect processes in Zr3AlC2 and Zr3SiC2. The MAX phase family is extended by demonstrating that Zr3(Al1–xSix)C2, and particularly compositions with x≈0.1, can be formed leading here to a yield of 59 wt%. It has been found that Zr3AlC2 - and by extension Zr3(Al1–xSix)C2 - formation rates benefit from the presence of traces of Si in the reactant mix, presumably through the in situ formation of ZrySiz phase(s) acting as a nucleation substrate for the MAX phase. To investigate the radiation tolerance of Zr3(Al1–xSix)C2, we have also considered the intrinsic defect properties of the end-members. A-element Frenkel reaction for both Zr3AlC2 (1.71 eV) and Zr3SiC2 (1.41 eV) Phases are the lowest energy defect reactions. For comparison we consider the defect processes in Ti3AlC2 and Ti3SiC2 Phases. It is concluded that Zr3AlC2 and Ti3AlC2 MAX Phases are more radiation tolerant than Zr3SiC2 and Ti3SiC2, respectively. Their applicability as cladding materials for nuclear fuel is discussed.
Nikolaos Kelaidis - One of the best experts on this subject based on the ideXlab platform.
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Electronic structures, bonding natures and defect processes in Sn-based 211 MAX Phases
Computational Materials Science, 2019Co-Authors: M A Hadi, Nikolaos Kelaidis, Alexander Chroneos, S. H. Naqib, A. K. M. A. IslamAbstract:Abstract The electronic structure, bonding natures, and defect processes of the new superconducting MAX phase Lu2SnC are investigated by using density functional theory, and are compared to other existing M2SnC Phases. The formation of M2SnC MAX Phases is exothermic and these compounds are intrinsically stable in agreement with experiment. The finite value of DOS, in addition to the d-resonance at the vicinity of the Fermi level, indicates a metallic nature and conductivity of M2SnC MAX Phases. The strength of the covalent M–C bond is higher than that of the covalent M–Sn bond. The calculated effective valence charge also indicates the dominance of covalency in the chemical bonding in the studied compounds. The charge transfer in M2SnC Phases indicates the ionic nature of their chemical bonds. The ionic character of their chemical bonds can also be understood from the spherical nature of charge distribution in their contour maps of electron charge density. Therefore, the overall bonding nature in the studied M2SnC MAX Phases is a combination of metallic, covalent, and, ionic. The bond length is directly proportional to the crystal radius, while bond covalency is inversely proportional to the crystal radius. Additionally, the Fermi surface topology is also investigated. Considering the intrinsic defect processes it is calculated that Nb2SnC is the material that is predicted to have better radiation tolerance.
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intrinsic defect processes and elastic properties of ti3ac2 a al si ga ge in sn MAX Phases
Journal of Applied Physics, 2018Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Petros-panagis Filippatos, M A Hadi, M E Fitzpatrick, Alexander ChroneosAbstract:Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3A...
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intrinsic defect processes and elastic properties of ti3ac2 a al si ga ge in sn MAX Phases
Journal of Applied Physics, 2018Co-Authors: Stavros Christopoulos, Nikolaos Kelaidis, Petros-panagis Filippatos, M A Hadi, M E Fitzpatrick, Alexander ChroneosAbstract:Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3AlC2 is nearly isotropic.Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C or N) have a combination of advantageous metallic and ceramic properties, and are being considered for structural applications particularly where high thermal conductivity and operating temperature are the primary drivers: for example in nuclear fuel cladding. Here, we employ density functional theory calculations to investigate the intrinsic defect processes and mechanical behaviour of a range of Ti3AC2 Phases (A = Al, Si, Ga, Ge, In, Sn). Based on the intrinsic defect reaction, it is calculated that Ti3SnC2 is the more radiation-tolerant 312 MAX phase considered herein. In this material, the C Frenkel reaction is the lowest energy intrinsic defect mechanism with 5.50 eV. When considering the elastic properties of the aforementioned MAX Phases, Ti3SiC2 is the hardest and Ti3SnC2 is the softest. All the MAX Phases considered here are non-central force solids and brittle in nature. Ti3SiC2 is elastically more anisotropic and Ti3A...
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defect processes of m3alc2 m v zr ta ti MAX Phases
Solid State Communications, 2017Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Alexander ChroneosAbstract:Abstract The interest on the M n+1 AX n Phases (M = early transition metal; A = group 13–16 element and X = C and/or N) stems from their combination of advantageous metallic and ceramic properties. Aluminium containing 312 MAX Phases in particular are deemed to enhance high-temperature oxidation resistance. In the present study, we use density functional theory calculations to study the intrinsic defect processes of M 3 AlC 2 MAX Phases (M = V, Zr, Ta, Ti). The calculations reveal that Ti 3 AlC 2 is the more radiation tolerant 312 MAX phase considered here. In Ti 3 AlC 2 the carbon Frenkel reaction is the lowest energy defect process with 3.17 eV. Results are discussed in view of recent experimental and theoretical results of related systems.
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Defect processes of M3AlC2 (M = V, Zr, Ta, Ti) MAX Phases
Solid State Communications, 2017Co-Authors: Stavros-richard G. Christopoulos, Nikolaos Kelaidis, Alexander ChroneosAbstract:The interest on the Mn+1AXn Phases (M = early transition metal; A = group 13–16 element and X = C and/or N) stems from their combination of advantageous metallic and ceramic properties. Aluminium containing 312 MAX Phases in particular are deemed to enhance high-temperature oxidation resistance. In the present study, we use density functional theory calculations to study the intrinsic defect processes of M3AlC2 MAX Phases (M = V, Zr, Ta, Ti). The calculations reveal that Ti3AlC2 is the more radiation tolerant 312 MAX phase considered here. In Ti3AlC2 the carbon Frenkel reaction is the lowest energy defect process with 3.17 eV. Results are discussed in view of recent experimental and theoretical results of related systems.
