Static And Dynamical Elastic Behavior Of Lu5ir4si10 Around Its First-Order Structural Phase Transition

Ultrasonic velocity measurements could be performed on a good quality single crystal of Lu5Ir4Si10 around its transition around 80 K. The behavior of the stiffness components demonstrates a first-order transition. The temperature dependence of the longitudinal elastic stiffness components C-11 and C-33 can be analyzed by the classical Landau theory and assuming a stricter coupling between the strain and the order parameter. A theoretical approach and experimental results are discussed.