Abstract
Tuning competing ordering mechanisms with hydrostatic pressure in the intermetallic compound reveals an intricate interplay of structure, magnetism, and superconductivity. Synchrotron x-ray diffraction and magnetic susceptibility measurements, both employing diamond anvil cell technologies, link a first-order structural phase transition to a doubling of the superconducting transition temperature. In contrast to the spin-dimer picture for , we deduce from x-ray absorption near-edge structure and dc magnetization measurements at ambient pressure that should possess only very small, itinerant magnetic moments. The pressure evolution of the superconducting transition temperature strongly suggests its enhancement is due to a difference in the phonon density-of-states with changed crystal symmetry.
- Received 5 August 2016
- Revised 4 January 2017
DOI:https://doi.org/10.1103/PhysRevB.95.125102
©2017 American Physical Society