A study of collective modes of Zr41Ti14Cu12.5Be22.5Fe10 bulk metallic glass and estimation of thermodynamic and elastic properties using pseudopotential theory

Author(s):  
Alkesh L. Gandhi ◽  
Aditya M. Vora
2016 ◽  
Vol 1141 ◽  
pp. 232-235
Author(s):  
Chaudhari Prakruti ◽  
Payal N. Chauhan ◽  
R.H. Joshi ◽  
Nisarg K. Bhatt ◽  
Brijmohan Y. Thakore

Using Hubbard-Beeby approach for phonon dynamics, in conjunction with our recently proposed model pseudopotential; phonon frequencies for longitudinal and transverse modes are computed and associated elastic properties of technologically important Zr-based Zr50Cu43Ag7 bulk metallic glass (BMG) are evaluated. Five different forms of the static local field correction functions, viz., Hartree etal. (H), Taylor et al. (T), Ichimaru and Utsumi et al. (IU), Farid et al. (F) and Sarkar et al. (S) are employed to investigate the influence of the screening effect on the vibrational dynamics of Zr50Cu43Ag7 BMG. Results for bulk modulus, modulus of rigidity, Poisson's ratio, Young modulus, propagation velocity of elastic waves and dispersion curves are studied. The theoretical computations are found to be in good agreement with the available experimental results, which confirms the use of our model pseudopotential to study elastic properties of such a glassy system.


2007 ◽  
Vol 48 (7) ◽  
pp. 1842-1845 ◽  
Author(s):  
R. Tarumi ◽  
M. Hirao ◽  
T. Ichitsubo ◽  
E. Matsubara ◽  
J. Saida ◽  
...  

2016 ◽  
Vol 1141 ◽  
pp. 91-95 ◽  
Author(s):  
Payal N. Chauhan ◽  
Chaudhari Prakruti ◽  
R.H. Joshi ◽  
Nisarg K. Bhatt ◽  
Brijmohan Y. Thakore

Different elastic properties of Pd-based Pd64Fe16P20 have been computed using two different forms of pseudopotential. Both the forms differ within the core region suggesting different degrees of orthogonalization and its r-dependence, while outside the core both preserves the Columbic nature. The only parameter, the core radius, separates these regions, and it is calculated using the realistic assumption based on the nearest neighbor distance. Further, five different forms of the local field correlated functions, namely, Hartree (H), Taylor (T), Ichimaru and Utsumi (IU), Farid et al. (F) and Sarkar et al. (S) are examined for better understanding regarding the screening effect on different elastic constants for Pd64Fe16P20 bulk metallic glass. The calculated results for the various elastic moduli, Poisson's ratio, sound velocity and phonon dispersion curve are all found to be in general agreement with the available experimental data. This confirms the applicability of the model pseudopotential to bulk metallic systems.


2007 ◽  
Vol 90 (21) ◽  
pp. 211901 ◽  
Author(s):  
Gang Duan ◽  
Mary Laura Lind ◽  
Katrien De Blauwe ◽  
Aaron Wiest ◽  
William L. Johnson

2016 ◽  
Vol 879 ◽  
pp. 767-772 ◽  
Author(s):  
Shinya Hosokawa ◽  
Masanori Inui ◽  
Yukio Kajihara ◽  
Tetsu Ichitsubo ◽  
Kazuhiro Matsuda ◽  
...  

To clarify microscopic elastic properties of a Pd40Ni40P20 bulk metallic glass, inelastic X-ray scattering (IXS) experiments were carried out using high-resolution IXS spectrometer installed at BL35XU/SPring-8. Clear longitudinal acoustic (LA) excitation modes are observed in the whole momentum transfer Q range up to ~22 nm-1. The microscopic sound velocity of the LA modes obtained from the Q → 0 limit of the dispersion relation is about 12% faster than the macroscopic value, suggesting the microscopic heterogeneity in the elastic properties of this BMG. In addition, transverse acoustic (TA) modes can be deduced from a detailed analysis of the IXS spectra. The microscopic Poisson’s ratio obtained from the ratio of the excitation energies of the TA and LA modes is 0.47 ± 0.04, larger than the macroscopic value of 0.40. Thus, the fragile nature of this BMG already found in the macroscopic sense is much enhanced in the microscopic view.


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