Ultrasonic attenuation in p‐Type Gasb at microwave frequencies

Abstract

An investigation is made of the variation of the attenuation coefficient for shear and longitudinal ultrasonic waves which propagate through monocrystalline p-type GaSb. The study was carried out for frequencies ranging from 0.6 to 1 GHz and in a range of temperatures from 5 to 300 OK. The measurements made by the pulse echo method are then compared with the theory of Woodruff and Ehrenreich and that of Bommel and Dransfeld.Nous avons btudib la variation du coefficient d'attbnuation d'ondes ultrasonores longitudinales et transversdes se propageant dans du GaSb monocristallin de type p, ceci pour des frbquences alIant de 0,5 B 1 GHz e t dans une gamme de tempbrature s'6tendant de 5 8, 300 OK. Les mesures faites par la methode de pulse echo sont ensuite comparQs aux theories de Woodruff et Ehrenreich e t Bommel et Dransfeld. IntroductionThe study of the propagation of high frequency acoustic waves in solids is now very used to examine some of the physical properties of materials. The attenuation of stress waves depends on different processes, mainly phonon-phonon interaction, phonon-charge carrier interaction, parallelism defect, dislocation damping, and so on.The aim of this work was to show the contribution and the importance of each of them in the attenuation of the sound wave. I n the present note the measurements of attenuation of longitudinal and shear waves are reported vs. temperature and frequency in p-type GaSb. The temperature range extended from 4 t o 300 O K , the frequency range from 0.5 to 1 GHz. Single crystal samples were obtained by the Czochralsky method, the growing axis being along the [ l l l ] direction. The measurements were made using the "pulse echo" method. The sample was excited by coupling with a piezoelectric quartz vibrating in forced oscillations in a resonant cavity.

Expression of acoustoelectric net gain in p-type GaSb

“…This expression neglects the attenuation due to phonon-phonon interaction. If we take the expression given by Woodruff and Ehrinreich the experimental results fit very well [3].…”