Elastic constants of the mixed valence compound Yb4As3 with extremely low carrier 0.001 per Yb atom have been measured by the ultrasonic method. We found that the transverse C44 mode exhibits a pronounced softening around the structural phase transition point at Tc = 292 K due to the charge ordering of Yb3+ ions along 〈111〉 direction. We interpret the softening of C44 with the coupling of the strain εyz, εxy and εxy to charge fluctuation mode possessing the electric quadrupole moment in Yb3+ linear chain.
- Charge ordering
- Elastic constants
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics
- Electrical and Electronic Engineering