Open AccessInelastic neutron scattering study of crystalline electric field excitations in a cubic compound PrMgNi4
Author(s) -
Yuka Kusanose,
Takahiro Onimaru,
Y. Yamane,
K. Umeo,
Toshiro Takabatake,
T. Guidi,
D. Le,
D. T. Adroja
Publication year - 2022
Publication title -
journal of physics. conference series
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.21
H-Index - 85
eISSN - 1742-6596
pISSN - 1742-6588
DOI - 10.1088/1742-6596/2164/1/012052
Subject(s) - excited state , quadrupole , physics , atomic physics , inelastic neutron scattering , inelastic scattering , ground state , singlet state , neutron , scattering , nuclear physics , optics
We performed inelastic neutron scattering experiments on PrMgNi 4 with the cubic MgSnCu 4 -type structure. The magnetic excitations were observed at 1.1, 2.5, 5.9, 10.7, and 11.7 meV. Since the energy of the excitations is constant for | Q | < 5 Å −1 , they are ascribed to the crystalline electric field (CEF) excitations of the Pr 3+ ions. We adopted CEF parameters of W = −3.3 K and x = 0.8 for the cubic T d point group to reproduce the strong excitations at 1.1, 10.7, and 11.7 meV. The calculated CEF level scheme reveals the Γ 3 doublet ground state with the quadrupolar degrees of freedom and the excited states of Γ 4 triplet (1.4 meV), Γ 1 singlet (3.4 meV), and Γ 5 triplet (13.5 meV). This scheme, however, does not explain the observed two excitations at 2.5 and 5.9 meV. These additional excitations may arise from splitting of the doublet by symmetry lowering due to excess Mg atoms occupying the Pr sites. This splitting is probably responsible for the absence of the long-range quadrupole order in PrMgNi 4 .