Elastic constants of filled skutterudite LaRu4As12

Abstract

Ultrasonic measurements with frequencies varying between 73 and 160 MHz were performed for the LaRu4As12 single crystal. This As-based filled skutterudite compound is a BCS-type superconductor with T sc as high as 10.3 K. In order to examine a presence of off-center rattling motion in LaRu4As12, we measured elastic constants CL111 = (C11 + 2C12 + 4C 44)/3 and CT111 = (C11 - C12 + 4C44)/3, which are related to longitudinal and transverse sound waves propagating along the [111] direction, respectively. No ultrasonic dispersion was found in the whole temperature range from 1.4 to 300 K. © Published under licence by IOP Publishing Ltd.