ECRYS - 93
J. Phys. IV France 03 (1993) C2-75-C2-78
Softening of the shear modulus C44 in (TaSe4)2I due to sliding charge density wavesR. BRITEL1, M. SAINT-PAUL1, P. MONCEAU1 and F. LEVY2
1 Centre de Recherches sur les Très Basses Températures, Laboratoire associé à l'Université Joseph Fourier, CNRS, BP. 166, 38042 Grenoble cedex 9, France
2 Institut de Physique Appliquée, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
Acoustic velocity of the shear mode C44 of quasi-one-dimensional (TaSe4)2I has been measured at 15 MHz frequency with the ultrasonic technique. It is found that the elastic constant C44 decreases when applied electric fields greater than the threshold ET are applied for charge-density wave (CDW) depinning. The decrease ΔC44/C44 ≈ 10-4 observed at 15 MHz for E ≈ 10 ET is two orders of magnitude smaller than the decrease reported at low frequency (kHz). Present results are compared with the effects of CDW depinning on the elastic properties predicted by several models.
© EDP Sciences 1993