Abstract
We have measured the elastic constant (-)/2 in URuSi by means of high-frequency ultrasonic measurements in pulsed magnetic fields [001] up to 61.8 T in a wide temperature range from 1.5 to 116 K. We found a reduction of (-)/2 that appears only in the temperature and magnetic field region in which URuSi exhibits a heavy-electron state and hidden order. This change in (-)/2 appears to be a response of the 5 electrons to an orthorhombic and volume conservative strain field - with symmetry. This lattice instability is likely related to a symmetry-breaking band instability that arises due to the hybridization of the localized electrons with the conduction electrons and is probably linked to the hidden-order parameter of this compound.
- Received 1 October 2013
DOI:https://doi.org/10.1103/PhysRevB.88.195150
©2013 American Physical Society