ScholarWorks@성균관대학교

초록

Two-dimensional honeycomb lattices, characterized by their low coordination numbers, provide a fertile platform for exploring various quantum phenomena due to the intricate interplay between competing magnetic interactions, spin-orbit coupling, and crystal electric fields. Beyond the widely studied Jeff = 1/2 honeycomb systems, S = 3/2 honeycomb lattices offer a promising alternative route for exploring spin-S Kitaev models and the effects of bond disorder. Herein, we present crystal structure, thermodynamic, neutron diffraction, and muon spin relaxation (mu SR) measurements, complemented by density functional theory (DFT) calculations on an unexplored 3d transition-metal-based compound Co2Te3O8, where Co2+ (S = 3/2) ions form a distorted honeycomb lattice in the crystallographic bc plane without any antisite disorder between constituent atoms. A clear )-type anomaly around TN approximate to 55 K in both magnetic susceptibility and specific heat data indicates the onset of a long-range ordered state below 55 K. The dominant antiferromagnetic interaction between S = 3/2 moments is evidenced by a relatively large negative Curie-Weiss temperature (theta CW = -103 K) derived from magnetic susceptibility data and supported by DFT calculations. The signature of long-range antiferomagnetic order state in the thermodynamic data is corroborated by neutron diffraction and mu SR results. Furthermore, mu SR experiments reveal the coexistence of static and dynamic local magnetic fields below TN, along with a complex magnetic structure that can be associated with XY-like antiferromagnet, as confirmed by neutron diffraction experiments.

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