Ultrasonic attenuation in the mixed state of vanadium

Electron-phonon interaction is studied in the mixed state of a type-II superconductor using a single-crystal vanadium sample. The ultrasonic-attenuation coefficient of longitudinal waves at 135 MHz and transverse waves at 255 MHz propagating along the [110] direction and parallel to the applied magnetic field are compared to the theory of Houghton and Maki. Good quantitative agreement is obtained with this sample which has a resistivity ratio of 20.