Dislocation damping and the ultrasonic attenuation in tin

Measurement of ultrasonic attenuation in single crystals of pure tin has been taken at 300 K for frequencies varying from 3 to 50 MHz and at different dislocation densities. There is a resonant behaviour in attenuation due to dislocation and the resonance frequency v_o increases with an increase in dislocation density A. Experimentally it has been observed that there is a linear variation between lnΛ and $\text{v}{}_{\mathrm{<mtext>o</mtext>}}{}^{\mathrm{<mtext>1</mtext><mtext>2</mtext>}}$. A systematic broadening of the resonance curve takes place with increasing dislocation density. The broadening of the resonance curve has been explained as being due to damping by mutual interaction between the dislocations. An estimate of dislocation damping has been made at different dislocation densities. The total damping due to phonons and electrons has also been estimated at 300K and 77 K.