[16a-S2_201-1~13] 10.4 Spintronics in semiconductor, topological material, superconductor, and multiferroics

12:00 PM - 12:15 PM JST(3:00 AM - 3:15 AM UTC)Presentation by Applicant for JSAP Young Scientists Presentation AwardEnglish Presentation

[16a-S2_201-12] Determination of Crystal Electric Field (CEF) of YbNi4Mg using Inelastic Neutron Scattering.

〇(DC)Ervin Naufal Arrasyid¹, Takanori Taniguchi^1,2, Shota Hashimoto¹, Gen Takahashi², Masaki Fujita^1,2 (1.Tohoku Univ. Phys., 2.Tohoku Univ. IMR)

Keywords:

Strongly Correlated Electron,Heavy Fermion Compound,4f electronic system

YbNi4Mg is a superheavy fermion with minimal site disorder, making it a strong candidate for quantum criticality studies. We investigated its crystal electric field (CEF) excitations using inelastic neutron scattering on polycrystalline samples derived from single crystals. The structure is confirmed as cubic MgCu4Sn-type (F-43m). Magnetic susceptibility indicates an effective moment of 4.54 muB/Yb, consistent with Yb3+ ions. Combined analysis reveals a Gamma7 doublet ground state, with excited Gamma8 quartet (47 K) and Gamma6 doublet (215 K) levels. Derived CEF parameters under tetrahedral symmetry are W = -8.7 K and x = -0.695. Similar to YbCu4Au, this doublet-quartet configuration implies that magnetic fields may activate electric quadrupolar degrees of freedom. YbNi4Mg serves as a key model for exploring the interplay of CEF physics, multipolar ordering, and quantum criticality.