Sound Velocity Study of Bechgaard Salts (TMTSF)2PF6 and (TMTSF)2ClO4

摘要: We have studied the elastic properties of Bechgaard salts (TMTSF)2PF6 and (TMTSF)2C104 through their Spin Density Wave (SDW) anion ordering transitions. Using a vibrating reed technique to measure sound velocity attenuation, we observed large softening immediately above SDW transition temperature, 12K, followed by hardening below transition. The results from strong dependence Tc on stress in most conducting direction, while loss screening conduction electrons yields value for long wavelength electron-phonon coupling constant. at 24K (TMTSF)2ClO4 is marked lattice that considerably larger than expected constant changes. Our interesting finding, however, observation series steps as Field Induced (FISDW) transitions are crossed increasing magnetic field low temperatures. fact small beginning cascade increase with field, even extrapolated an unexpected result present theory may indicate more direct stiffness order parameter.