Pressure dependency of electron-phonon renormalization in diamond

2016 ◽  
Vol 70 ◽  
pp. 132-136 ◽  
Author(s):  
Ali Kazempour ◽  
Toktam Morshedloo
1969 ◽  
Vol 47 (10) ◽  
pp. 1107-1116 ◽  
Author(s):  
J. P. Carbotte ◽  
R. C. Dynes ◽  
P. N. Trofimenkoff

We have made detailed first principle calculations of the phonon contribution to the renormalization of the electronic effective mass of a number of simple metals and alloys. The phonon frequencies and polarization vectors are generated from the interatomic force constants for the material. The force constants are taken from a Born – von Kármán analysis of the experimental phonon dispersion curves determined by inelastic neutron scattering. The electron–phonon interaction is treated using pseudo-potential theory which relates the coupling constant to the electron–ion form factor. For a spherical Fermi surface it is then possible to evaluate numerically the expression for the effective mass with no further approximations. We compare the results obtained with previous work when available and with experiment otherwise.


2018 ◽  
Vol 53 (12) ◽  
pp. 1681-1696 ◽  
Author(s):  
Sérgio Costa ◽  
Thomas Bru ◽  
Robin Olsson ◽  
André Portugal

This paper details a complete crush model for composite materials with focus on shear dominated crushing under a three-dimensional stress state. The damage evolution laws and final failure strain conditions are based on data extracted from shear experiments. The main advantages of the current model include the following: no need to measure the fracture toughness in shear and transverse compression, mesh objectivity without the need for a regular mesh and finite element characteristic length, a pressure dependency of the nonlinear shear response, accounting for load reversal and some orthotropic effects (making the model suitable for noncrimp fabric composites). The model is validated against a range of relevant experiments, namely a through-the-thickness compression specimen and a flat crush coupon with the fibres oriented at 45° and 90° to the load. Damage growth mechanisms, orientation of the fracture plane, nonlinear evolution of Poisson's ratio and energy absorption are accurately predicted.


2018 ◽  
Vol 97 (24) ◽  
Author(s):  
M. Maschek ◽  
J.-P. Castellan ◽  
D. Lamago ◽  
D. Reznik ◽  
F. Weber

1990 ◽  
Vol 17 (6) ◽  
pp. 717-719 ◽  
Author(s):  
Mark H. Thiemens ◽  
Teresa Jackson

2011 ◽  
Vol 75 (5) ◽  
pp. 2597-2610 ◽  
Author(s):  
S. A. Hunt ◽  
A. M. Walker ◽  
R. J. McCormack ◽  
D. P. Dobson ◽  
A. S. Wills ◽  
...  

AbstractThe thermal diffusivity of diopside, jadeite and enstatite were measured at simultaneous pressures and temperatures of up to 7 GPa and 1200 K using the X-radiographic Ångström method. The measurements herein show that the pressure dependency of thermal diffusivity in pyroxenes is significantly greater than in olivine or garnet and that in the MORB-layer of a subducting slab the thermal diffusivity of pyroxenes are a factor of 1.5 greater than that of olivine. The temperature dependence of all the data sets is well described by a low-order polynomial fit to 1/K and the pressure dependence is exponential in 1/K, formulations which are consistent with the damped harmonic oscillator model for thermal properties.


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