ELASTIC EFFECTS OF AN AC-DRIVEN CHARGE-DENSITY WAVE IN TAS3

Young's modulus of o-TaS3 was measured while its charge-density wave (CDW) was driven by a square-wave electrical bias at frequency f(I), with 100 Hz < f(I) < 1 MHz. The modulus of the ac-driven state decreases until f(I) reaches a few kHz, then increases toward the value for the stationary state at larger f(I). Such dramatic variations at relatively low frequency imply a relaxational origin of the effect. Evidence is presented for a broad distribution of characteristic times. Analogies between these findings and those for dielectric response, broadband noise, and overshoot current suggest that all low-frequency dynamic phenomena, elastic as well as electrical, may have a common relaxational origin.