Abstract
The pressure evolution of the magnetic properties of the heavy fermion compound was investigated by single crystal neutron magnetic diffraction and electrical resistivity experiments under applied pressure. From the neutron magnetic diffraction data, up to , we found no changes in the magnetic structure or in the ordering temperature . However, the increase of pressure induces an interesting spin rotation of the ordered antiferromagnetic moment of into the tetragonal plane. From the electrical resistivity measurements under pressure, we have mapped the evolution of and the maximum of the temperature dependent electrical resistivity () as a function of the pressure (). To gain some insight into the microscopic origin of the observed spin rotation as a function of pressure, we have also analyzed some macroscopic magnetic susceptibility data at ambient pressure for pure and Cd-doped using a mean-field model including tetragonal crystalline electric field (CEF). The analysis indicates that these compounds have a Kramers doublet -type ground state, followed by a first excited state at and a second excited state at for and for . The evolution of the magnetic properties of as a function of Cd doping and the rotation of the direction of the ordered moment for the compound under pressure suggest important changes of the single ion anisotropy of induced by applying pressure and Cd doping in these systems. These changes are reflected in modifications in the CEF scheme that will ultimately affect the actual ground state of these compounds.
- Received 20 July 2019
- Revised 25 September 2019
DOI:https://doi.org/10.1103/PhysRevB.100.165133
©2019 American Physical Society