Comparative Raman Scattering Study of Crystal Field Excitations in Co-based Quantum Magnets

Banasree S. Mou; Xinshu Zhang; Li Xiang; Yuanyuan Xu; Ruidan Zhong; Robert J. Cava; Haidong Zhou; Zhigang Jiang; Dmitry Smirnov; Natalia Drichko; Stephen M. Winter

doi:10.1103/PhysRevMaterials.8.084408

paper

Comparative Raman Scattering Study of Crystal Field Excitations in Co-based Quantum Magnets

arXiv:2403.11980 · doi:10.1103/PhysRevMaterials.8.084408

Abstract

Co-based materials have recently been explored due to potential to realise complex bond-dependent anisotropic magnetism. Prominent examples include Na $_{2}$ Co $_{2}$ TeO $_{6}$ , BaCo $_{2}$ (AsO $_{4}$ ) $_{2}$ , Na $_{2}$ BaCo(PO $_{4}$ ) $_{2}$ , and CoX $_{2}$ (X = Cl, Br, I). In order to provide insight into the magnetic interactions in these compounds, we make a comparative analysis of their local crystal electric field excitations spectra via Raman scattering measurements. Combining these measurements with theoretical analysis confirms the validity of $j_{eff} = 1/2$ single-ion ground states for all compounds, and provides accurate experimental estimates of the local crystal distortions, which play a prominent role in the magnetic couplings between spin-orbital coupled Co moments.

11 pages, 7 figures