Elastic anomalies at the magnetic phase transitions of TbTe3. (August 2016) - Saint-Paul, M.
Abstract: We report sound velocity and ultrasonic attenuation measurements in the vicinity of the successive magnetic phase transitions T mag1 ~6.5 K, T mag2 ~5.8 K and T mag3 ~5.3 K in the charge density wave TbTe3 compound. A detailed investigation of the critical contributions to the temperature dependences of the sound velocity and ultrasonic attenuation is presented. Anisotropic stress dependences ∂ T m a g 1 / ∂ σ found at the antiferromagnetic phase transition T mag1 is associated with the layered structure of this compound. An abrupt step-like increase in the velocity and a sharp peak in the attenuation are observed with the longitudinal and shear modes at the lock-in magnetic phase transition T mag3 =5.3 K. The critical velocity and attenuation behaviors in the high temperature paramagnetic above T mag1 are described in terms of a phenomenological dynamic scaling expression. Highlights: Large anomalies in the velocity and ultrasonic attenuation at the magnetic phase transitions of TbTe3 . Critical behavior is analyzed.