Self-Detection of Ultrasonic Standing Waves and Anomaly of Young’s Modulus at Uniaxial Extension Whiskers of the Quasi-One-Dimensional Conductor TaS3

Mechanical vibrations of whiskers of the quasi-one-dimensional conductor TaS3 that appear at the application of an ac voltage above the threshold value for the sliding of a charge density wave have been studied by the heterodyning method. It has been shown that the highest frequency modes correspond to the excitation of longitudinal ultrasonic standing waves. A sharp minimum of the frequencies of ultrasonic resonances at a critical tension of εc ≈ 0.7% has been detected in the region of transition of the charge density wave to a new state.