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  Huesges, Z.; Kliemt, K.; Krellner, C.; Sarkar, R.; Klauß, H.-H.; Geibel, C.; Rotter, M.; Novák, P.; Kunes, J.; Stockert, O.: Analysis of the crystal electric field parameters of YbNi₄P₂. New Journal of Physics 20 (2018), p. 073021/1-10

10.1088/1367-2630/aace35
Open Access Version

Abstract:
The crystal electric field (CEF) scheme of YbNi4P2 is determined, based on experimental data from inelastic neutron scattering, heat capacity, susceptibility and NMR measurements. Despite the tetragonal crystal structure, 9 parameters are needed to describe the crystal field in YbNi4P2 due to the orthorhombic site symmetry of the Yb ion. A large basal plane anisotropy is detected by the local probe NMR. Our analysis yields CEF excitation energies of 8.5 meV, 12.5 meV and roughly 30meV and a ground state wave function that is dominated by the 5/2 state. Furthermore, we present an analysis of the CEF scheme based on DFT calculations, which confirms the large basal plane anisotropy.