Neutron spectroscopy study on crystalline electric field excitations in NdB

Yamauchi, Hiroki   ; Metoki, Naoto   ; Watanuki, Ryuta*; Hong, T.*; Fernandez-Baca, J. A.*; Hagihara, Masato   ; Masuda, Takatsugu*; Yoshizawa, Hideki*; Ito, Shinichi*

The -electron states of NdB were determined by observing crystalline electric field (CEF) excitations with inelastic neutron scattering experiments. Our analysis yields CEF excitation energies of 2.8, 12.4, 17.2, and 25.4 meV. The -electron states are simply described by one of -multiplets with negligibly small mixing. The ground state is the pseudo-quartet consist of the ground doublet dominated by and the first excited doublet dominated by at 2.8 meV, which is consistent with magnetic specific heat and entropy reported in earlier study. The simple -electron states in NdB are the consequence of the strong uniaxial and in-plane isotropic CEF potential due to the local structure of Nd ions with point symmetry .