Abstract
The rare-earth-based ternary intermetallic compounds ( = rare earth, = transition metal, = Si, Ge, Ga, In) have attracted considerable interest due to a wide range of interesting low-temperature properties. Here we investigate the magnetic state of using neutron diffraction, muon spin relaxation (), and inelastic neutron scattering (INS). This compound appears anomalous among the series since it was proposed to order ferromagnetically, whereas others in this series are antiferromagnets. Although some members of the series have been reported to form ordered superstructures, our data are well described by adopting the -type structure with a single Nd site, and we do not find evidence of superlattice peaks in neutron diffraction. Our results confirm the onset of long-range magnetic order below K, where the whole sample enters the ordered state. Neutron diffraction measurements establish the presence of a ferromagnetic component in this compound, as well as an antiferromagnetic one which has a propagation vector with a temperature-dependent , and moments orientated exclusively along the axis. measurements suggest that these components coexist on a microscopic level, and therefore the magnetic structure of is predominantly ferromagnetic, with a sinusoidally modulated antiferromagnetic contribution which reaches a maximum amplitude at 11 K and becomes smaller upon further decreasing the temperature. INS results show the presence of crystalline electric field (CEF) excitations above , and from our analysis we propose a CEF level scheme.
- Received 20 June 2019
- Revised 27 September 2019
DOI:https://doi.org/10.1103/PhysRevB.100.134423
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