J. Phys. IV France 129 (2005) 55-59
Pressure acoustic spectroscopy of cyclic compoundsB.B.J. Linde1 and U.M. Esanov2
1 Institute of Experimental Physics, University of Gdansk, ul. Wita Stwosza 57, 80-952 Gdansk, Poland
2 Institute of Physics and Techniques, Academy of Sciences of Turkmenistan & TURKMENGAS
In this paper there are presented the investigations of high pressure influence on processes of absorption in some Kneser liquids - in the frequency range of 30 - 110 MHz and for pressures between 0.1 and 100 MPa. The experimental results of the dependence of absorption on pressure for measured liquids support the assumption that acoustic relaxation in these compounds is caused by Kneser's processes. From the obtained results we can conclude that: the absorption decreases and the relaxation time shortens when the pressure grows, which is in accordance with predictions for vibrational relaxation. Hence, the increase of pressure results in the increasing of the number of collisions, thus increasing the probability of energy transfer, i.e. reducing the relaxation time and acoustical absorption. The data obtained from the measurements were interpreted according to the theory of isolated binary collisions and allowed to estimate the molecule diameter.
© EDP Sciences 2005