We report on the magnetic and elastic properties of ${\mathrm{Er}}_3{\mathrm{Ru}}_4{\mathrm{Al}}_{12}$ in static and pulsed magnetic fields up to 58 T. From the ultrasound results, we obtain evidence for a phase transition at 2 K related to magnetic ordering. Furthermore, in the paramagnetic state, ${\mathrm{Er}}_3{\mathrm{Ru}}_4{\mathrm{Al}}_{12}$ shows pronounced anomalies in the magnetization and elastic moduli as a function of temperature and magnetic field. We explain our findings using a crystal-electric-field (CEF) model that includes quadrupolar interactions and propose a CEF level scheme for this material. However, the CEF effects cannot explain all field-induced anomalies, which indicates that refined models are needed for explaining these.

• Received 8 January 2020
• Revised 28 February 2020
• Accepted 28 February 2020

DOI:https://doi.org/10.1103/PhysRevB.101.094415