First-principle calculations of structural, elastic and thermodynamic properties of Fe–B compounds

Li, Liuhui; Hu, L.; Wei, B.

doi:10.1016/j.intermet.2013.11.007

Cited by 79 publications

(18 citation statements)

References 41 publications

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“…A comparison with the experimental information may be found in Table 2. In the case of the FeB2 compound we reported in Table 2 the ground state found by Kolmogorov et al [39] and confirmed later by Li et al [40]. Indeed, Kolmogorov et al [39] found that in the case of FeB 2 an orthorhombic structure, oP12, is more stable than the other structures.…”

Section: Resultssupporting

confidence: 81%

Enthalpies of Formation of Transition Metal Diborides: A First Principles Study

Colinet

Tedenac

2015

Crystals

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Abstract:The enthalpies of formation of transition metals diborides in various structures have been obtained from density functional theory (DFT) calculations in order to determine the ground state at T = 0 K and p = 0. The evolution of the enthalpies of formation along the 3D, 4D, and 5D series has been correlated to the considered crystal structures. In the whole, the calculated values of the enthalpies of formation of the diborides in their ground state are in good agreement with the experimental ones when available. The calculated values of the lattice parameters at T = 0 K of the ground state agree well with the experimental values. The total and partial electronic densities of states have been computed. Special features of the transition metal electronic partial density of states have been evidenced and correlated to the local environment of the atoms.

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Section: Resultssupporting

confidence: 81%

Enthalpies of Formation of Transition Metal Diborides: A First Principles Study

Colinet

Tedenac

2015

Crystals

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“…Ni 3 P is less compressible than pure hcp-Fe or iron phosphide phase, including Fe 3 P [19,35]. Moreover, first-principles calculations on Ni 3 P, Fe 3 P, and pure hcp-Fe suggest that the shear modulus of Ni 3 P is lower than Fe 3 P and pure hcp-Fe by approximately 30% and 20%, respectively [63,70,71]. The higher incompressibility and lower shear modulus of Ni 3 P are consistent with the decrease of shear wave velocity of Fe under pressure when adding Ni to Fe-compounds [8].…”

Section: Implications For Planetary Coresmentioning

confidence: 99%

Structure and Behavior of the Ni End-Member Schreibersite Ni3P under Compression to 50 GPa

2020

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To better understand the potential presence of light element alloys of Fe and Ni in the Earth’s interior, the crystal structure and compressional behavior of the Ni-P binary compound, schreibersite (Ni3P), have been investigated using synchrotron X-ray diffraction experiments. Both powder and two single-crystal samples of synthetic Ni3P (in different orientations with respect to the loading axis of the diamond anvil cell) were compressed up to approximately 50 GPa at ambient temperature. The compressional data obtained for Ni3P were fitted with a 3rd order Birch–Murnaghan equation of state. All data indicated that the c/a ratio of unit cell parameters remained approximately constant up to about 30 GPa but then increased progressively with pressure, exhibiting a second slight discontinuity at approximately 40 GPa. The changes in unit cell parameters at ~30 GPa and ~40 GPa suggested discontinuous changes in magnetic ordering. Moreover, the threshold of these subtle discontinuities is sensitive to the stress state and orientation of the crystal in the diamond anvil cell. This study is the first report on the compressional behavior of both powder and single-crystal schreibersite at high-pressure (up to 50 GPa). It offers insights into the effects of Ni3P components on the compressional behavior of the Earth’s core.

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“…Approximation of an ideal mixing is used to compute S conf (T) [46,47]. Details of calculating F vib (V,T), F el (V,T), and TS conf (T) contributions are provided and widely discussed in the pertinent literature [24,[48][49][50][51][52]. 1.…”

Section: Computationsmentioning

confidence: 99%

Deformation induced twinning in hcp/bcc Al10Hf25Nb5Sc10Ti25Zr25 high entropy alloy – microstructure and mechanical properties

Rogal

Wdowik

Szczerba

et al. 2021

Materials Science and Engineering: A

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High-entropy alloys of hexagonal structure commonly revealing high strength but very limited ductility, still remain a challenging task. Advanced strategy is proposed in present work in order to develop high-entropy alloy of chemical composition Al 10 Hf 25 Nb 5 Sc 10 Ti 25 Zr 25 at.%. Crystallographic features and microstructures of as-cast and annealed Al 10 Hf 25 Nb 5 Sc 10 Ti 25 Zr 25 at.% alloy are characterized by X-ray diffraction, scanning and highresolution transmission electron microscopies, whereas differential scanning calorimetry is used to follow temperature-induced phase transformation in the as-cast system. The cast alloy reveals microstructure containing fine orthorhombic needle-like plates within solid-solution of body-centered cubic structure. Such a dual-phase microstructure leads to enhanced combination of high strength and good ductility. The alloy annealed at 1000 • C for 5h acquires tensile strength increased by 38%, yield strength more than ten times higher, and almost 3-fold increased plasticity as compared with the as-cast alloy. Its Vickers hardness becomes higher by 25%. These meaningful changes are associated with temperature-induced transformation of its microstructure, which include diffusion growth of hexagonal plates enriched in Zr, Sc, and Hf within the bcc-type matrix enriched in Nb and Ti. Microstructure reveals twins within the hcp plates which plays a crucial role in plastic deformation and strengthening of the materials. Ab initio calculations based on the density functional theory are employed to investigate stability and mechanical properties of bcc, hcp, and orthorhombic phases of 5-component Al 15 Hf 25 Sc 10 Ti 25 Zr 25 at.% and 6-component Al 10 Hf 25 Nb 5 Sc 10 Ti 25 Zr 25 at.% high entropy alloys. The hcp phases of both systems are energetically preferred at T = 0 K, brittle and have rather high Vickers hardness. The bcc phases of both high-entropy alloys stabilize and become energetically favored above 790 K for Al 15 Hf 25 Sc 10-Ti 25 Zr 25 at.% and 1150 K for Al 10 Hf 25 Nb 5 Sc 10 Ti 25 Zr 25 at.% alloys. Depending on the type of crystallographic structure, the phases enriched in 5 at% of Nb show either reduced or enhanced values of their elastic moduli and Vickers hardness as compared to the Nb-free phases. No transformation from brittle to ductile state and vice versa is observed upon doping the considered phases of Al-Hf-Sc-Ti-Zr system with Nb.

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First-principle calculations of structural, elastic and thermodynamic properties of Fe–B compounds

Cited by 79 publications

References 41 publications

Enthalpies of Formation of Transition Metal Diborides: A First Principles Study

Enthalpies of Formation of Transition Metal Diborides: A First Principles Study

Structure and Behavior of the Ni End-Member Schreibersite Ni3P under Compression to 50 GPa

Deformation induced twinning in hcp/bcc Al10Hf25Nb5Sc10Ti25Zr25 high entropy alloy – microstructure and mechanical properties

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