Abstract
The elastic properties of in the high magnetic field region above 40 T, over a wide temperature range from 1.5 to 120 K, were systematically investigated by means of high-frequency ultrasonic measurements. The investigation was performed at high magnetic fields to better investigate the innate bare -electron properties, since the unidentified electronic thermodynamic phase of unknown origin, the so-called “hidden order” (HO), and associated hybridization of conduction and electrons hybridization) are suppressed at high magnetic fields. From the three different transverse modes we find contrasting results; both the and symmetry modes and show elastic softening that is enhanced above 30 T, while the characteristic softening of the symmetry mode is suppressed in high magnetic fields. These results underscore the presence of a hybridization-driven lattice instability in . However, the results from this work cannot be explained by using existing crystalline electric field schemes applied to the quadrupolar susceptibility in a local configuration. Instead, we present an analysis based on a band Jahn-Teller effect.
- Received 16 February 2018
- Revised 31 March 2018
DOI:https://doi.org/10.1103/PhysRevB.97.155137
©2018 American Physical Society