The Experts below are selected from a list of 315 Experts worldwide ranked by ideXlab platform

David F. Welch - One of the best experts on this subject based on the ideXlab platform.

  • hexagonal structured e nbn ultra incompressibility high Shear Rigidity and a possible hard superconducting material
    Scientific Reports, 2015
    Co-Authors: Xuebing Wang, Xintong Qi, Xuefei Li, David F. Welch, Ting Chen, Baosheng Li
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.

  • Hexagonal-structured ε-NbN: ultra-incompressibility, high Shear Rigidity, and a possible hard superconducting material.
    Scientific reports, 2015
    Co-Authors: Yongtao Zou, Xuebing Wang, David F. Welch, Ting Chen, Pinwen Zhu, Bingbing Liu, Tian Cui
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.

Kostya Trachenko - One of the best experts on this subject based on the ideXlab platform.

  • Explaining the low-frequency Shear elasticity of confined liquids.
    Proceedings of the National Academy of Sciences of the United States of America, 2020
    Co-Authors: Alessio Zaccone, Kostya Trachenko
    Abstract:

    Experimental observations of unexpected Shear Rigidity in confined liquids, on very low frequency scales on the order of 0.01 to 0.1 Hz, call into question our basic understanding of the elasticity of liquids and have posed a challenge to theoretical models of the liquid state ever since. Here we combine the nonaffine theory of lattice dynamics valid for disordered condensed matter systems with the Frenkel theory of the liquid state. The emerging framework shows that applying confinement to a liquid can effectively suppress the low-frequency modes that are responsible for nonaffine soft mechanical response, thus leading to an effective increase of the liquid Shear Rigidity. The theory successfully predicts the scaling law [Formula: see text] for the low-frequency Shear modulus of liquids as a function of the confinement length L, in agreement with experimental results, and provides the basis for a more general description of the elasticity of liquids across different time and length scales.

  • Helium at elevated pressures: Quantum liquid with non-static Shear Rigidity
    Journal of Applied Physics, 2013
    Co-Authors: Dima Bolmatov, Vadim V. Brazhkin, Kostya Trachenko
    Abstract:

    The properties of liquid helium have always been a fascinating subject to scientists. The phonon theory of liquids taking into account liquid non-static Shear Rigidity is employed here for studying internal energy and heat capacity of compressed liquid 4-He. We demonstrate good agreement of calculated and experimental heat capacity of liquid helium at elevated pressures and supercritical temperatures. Unexpectedly helium remains a quantum liquid at elevated pressures for a wide range of temperature supporting both longitudinal and transverse-like phonon excitations. We have found that in the very wide pressure range 5 MPa-500 MPa liquid helium near melting temperature is both solid-like and quantum.

  • helium at elevated pressures quantum liquid with non static Shear Rigidity
    Journal of Applied Physics, 2013
    Co-Authors: Dima Bolmatov, Vadim V. Brazhkin, Kostya Trachenko
    Abstract:

    The properties of liquid helium have always been a fascinating subject to scientists. The phonon theory of liquids, taking into account liquid non-static Shear Rigidity, is employed here for studying internal energy and heat capacity of compressed liquid 4He. We demonstrate the good agreement of calculated and experimental heat capacity of liquid helium at elevated pressures and supercritical temperatures. Unexpectedly, helium remains a quantum liquid at elevated pressures for a wide range of temperature supporting both longitudinal and transverse-like phonon excitations. We have found that in the very wide pressure range of 5 MPa-500 MPa, liquid helium near melting temperature is both solid-like and quantum.

Xuebing Wang - One of the best experts on this subject based on the ideXlab platform.

  • hexagonal structured e nbn ultra incompressibility high Shear Rigidity and a possible hard superconducting material
    Scientific Reports, 2015
    Co-Authors: Xuebing Wang, Xintong Qi, Xuefei Li, David F. Welch, Ting Chen, Baosheng Li
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.

  • Hexagonal-structured ε-NbN: ultra-incompressibility, high Shear Rigidity, and a possible hard superconducting material.
    Scientific reports, 2015
    Co-Authors: Yongtao Zou, Xuebing Wang, David F. Welch, Ting Chen, Pinwen Zhu, Bingbing Liu, Tian Cui
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.

Tian Cui - One of the best experts on this subject based on the ideXlab platform.

  • Hexagonal-structured ε-NbN: ultra-incompressibility, high Shear Rigidity, and a possible hard superconducting material.
    Scientific reports, 2015
    Co-Authors: Yongtao Zou, Xuebing Wang, David F. Welch, Ting Chen, Pinwen Zhu, Bingbing Liu, Tian Cui
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.

Baosheng Li - One of the best experts on this subject based on the ideXlab platform.

  • hexagonal structured e nbn ultra incompressibility high Shear Rigidity and a possible hard superconducting material
    Scientific Reports, 2015
    Co-Authors: Xuebing Wang, Xintong Qi, Xuefei Li, David F. Welch, Ting Chen, Baosheng Li
    Abstract:

    Exploring the structural stability and elasticity of hexagonal e-NbN helps discover correlations among its physical properties for scientific and technological applications. Here, for the first time, we measured the ultra-incompressibility and high Shear Rigidity of polycrystalline hexagonal e-NbN using ultrasonic interferometry and in situ X-ray diffraction, complemented with first-principles density-functional theory calculations up to 30 GPa in pressure. Using a finite strain equation of state approach, the elastic bulk and Shear moduli, as well as their pressure dependences are derived from the measured velocities and densities, yielding BS0 = 373.3(15) GPa, G0 = 200.5(8) GPa, ∂BS/∂P = 3.81(3) and ∂G/∂P = 1.67(1). The hexagonal e-NbN possesses a very high bulk modulus, rivaling that of superhard material cBN (B0 = 381.1 GPa). The high Shear Rigidity is comparable to that for superhard γ-B (G0 = 227.2 GPa). We found that the crystal structure of transition-metal nitrides and the outmost electrons of the corresponding metals may dominate their pressure dependences in bulk and Shear moduli. In addition, the elastic moduli, Vickers hardness, Debye temperature, melting temperature and a possible superconductivity of hexagonal e-NbN all increase with pressures, suggesting its exceptional suitability for applications under extreme conditions.