Orientation dependence of internal friction in artificial single crystals of ice

Abstract The internal friction of artificial single crystals of ice is studied by the flexural vibration method, changing temperature, frequency and angle θ between the crystal c -axis and the long axis of the specimen. The height of the main peak in the curve of the internal friction (tan δ) versus temperature depends strongly on the angle θ. The maximum damping (tan δ max ) increased with increase in the angle θ up to nearly 60° and decreased a little for values of θ greater than 60°. The results of the experiments except for θ = 0° show that the internal friction peak is caused by a single relaxation phenomenon, the relaxation time of which is τ = τ 0 exp (H/kT). Values of τ 0 and H are 1.66 × 10 −16 s and 0.60 eV, respectively. The data are compared with the other experiments and are discussed with special reference to the theoretical treatments by Bass. The orientation dependence of tan δ max is found to be consistent with the theoretical prediction.