scholarly journals Brillouin Scattering and Elastic Constants of Potassium Bromide

1973 ◽  
Vol 46 (10) ◽  
pp. 3031-3035 ◽  
Author(s):  
Hiroatsu Matsuura ◽  
Tatsuo Miyazawa
1995 ◽  
Vol 52 (12) ◽  
pp. R8707-R8710 ◽  
Author(s):  
D. Fioretto ◽  
G. Carlotti ◽  
G. Socino ◽  
S. Modesti ◽  
C. Cepek ◽  
...  

1997 ◽  
Vol 82 (6) ◽  
pp. 3152-3154 ◽  
Author(s):  
K. Kamitani ◽  
M. Grimsditch ◽  
J. C. Nipko ◽  
C.-K. Loong ◽  
M. Okada ◽  
...  

1999 ◽  
Vol 593 ◽  
Author(s):  
A.C. Ferrari ◽  
J. Robertson ◽  
R. Pastorelli ◽  
M.G. Beghi ◽  
C.E. Bottani

ABSTRACTThe elastic constants of thin Diamond-Like Carbon (DLC) films supply important information, but their measurement is difficult. Standard nanoindentation does not directly measure the elastic constants and has strong limitations particularly in the case of hard thin films on softer substrates, such as tetrahedral amorphous carbon on Si. Surface acoustic waves provide a better mean to investigate elastic properties. Surface Brillouin scattering (SBS) intrinsically probes acoustic waves of the wavelength which is appropriate to test the properties of films in the tens to hundreds of nanometers thickness range. SBS can be used to derive all the isotropic elastic constants of hard-on-soft and soft-on-hard amorphous carbon films of different kinds, with thickness down to less than 10 nm. The results help to resolve the previous uncertainties in mechanical data. The Young's modulus of tetrahedral amorphous carbon (ta-C) turns out to be lower than that of diamond, while the moduli of hydrogenated ta-C (ta-C:H) are considerably lower than those of ta-C because of the weakening effect of C-H bonding.


1999 ◽  
Vol 11 (21) ◽  
pp. 4157-4162 ◽  
Author(s):  
C Ecolivet ◽  
M Saint-Paul ◽  
G Dhalenne ◽  
A Revcolevschi

1982 ◽  
Vol 60 (3) ◽  
pp. 287-298 ◽  
Author(s):  
S. C. Rand ◽  
B. P. Stoicheff

The elastic constants and Pockels coefficients of CH4 and CD4 single crystals near their triple points have been determined using high-resolution Brillouin spectroscopy. For CH4 at 90.4 K, the elastic constants are C11 = 19.57 ± 0.30, C12 = 14.46 ± 0.20, C44 = 9.20 ± 0.15 kbar, and the ratios of the Pockels coefficients are p12/p11 = 1.031 ± 0.035 and p44/p11 = 0.069 ± 0.010. For CD4 at 89.2 K, C12 = 20.04 ± 0.30, C12 = 15.00 ± 0.25, C44 = 9.15 ± 0.15 kbar, and p12/p11 = 1.027 ± 0.020, P44/p11 = 0.138 ± 0.010. The velocities of the low-frequency transverse modes in CH4 and CD4 are anomalously slow in the [Formula: see text] direction, indicative of rotational–translational coupling of molecules. Isotopic differences are also evident: the Pockels coefficient p44 in CD4 is double that in CH4; and the velocities of both transverse modes in the principle directions [Formula: see text], [Formula: see text], and [Formula: see text] are in the ratio V(CH4)/V(CD4) = 1.130 instead of 1.118 as expected from the isotopic mass ratio.


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