Measurement of the acoustic nonlinearity parameter in 1-alkanols

We present a harmonic generation method based on a pitch-catch experimental setup and the calculation of the corresponding nonlinear parameter in 1-alkanols, from methanol to 1-decanol. By focusing a 14 MHz ultrasonic toneburst through a spherical quartz lens in these alcohols, a second harmonic is produced and measured as a function of distance by a 28 MHz piezoelectric transducer placed near the focus. By extracting the point where the second harmonic power is at a maximum in each liquid, the corresponding nonlinear parameter is then computed with a model developed by Germain et al. The preliminary results from this experiment are in reasonable agreement with the values found in the literature for primary alcohols and support the idea that the nonlinear parameter is dependent on the chain structure.