Nonequilibrium acoustic phonons in diamond: generation, scattering, reflection

A heated thin gold film as a generator of nonequilibrium phonons in diamond was studied both theoretically and experimentally. The cooling times tau(C ) of the film obtained theoretically are of the order of experimental bolom etric response widths. Since tau(C) > tau(B) (time of phonon ballistic prop agation in the sample under study), the "gold" phonon generator proved to b e inadequate. A novel method of phonon generation is proposed - photoexcita tion of buried implanted layer that allowed us to resolve the arrival of LA and TA phonons. Comparison of the heat pulses observed with those calculat ed by the Monte Carlo method yields the constant of elastic phonon scatteri ng A(SCAT) = 2 x 10(-44) s(-3), which coincides with that calculated by tak ing into account scattering only by the isotopes C-13. (C) 1999 Elsevier Sc ience B.V. All rights reserved.