First-principles study of the phonons and crystal-field excitations in the magnetodielectric regime of Ce2O3

The mechanism associated with the giant magnetodielectric effect that was recently reported in A-type Ce2O3 remains an open question [1]. Recent Raman measurements indicate that there are vibronic excitations in its magnetodielectric regime, which in turn suggest a strong coupling between its spin, lattice and electronic degrees of freedom [2]. In this study, we apply density functional theory with LDA+U+SOC functional to disentangle the multiple coupling channels. The results show that strong coupling exists between the phonons and crystal-field excitations. This study helps to elucidate the underlying mechanism of the strong magnetodielectric effect in Ce2O3.

[1] T. Kolodiazhnyi, H. Sakurai, M. Avdeev, T. Charoonsuk, K. V. Lamonova, Y. G. Pashkevich, and B. J. Kennedy, Phys. Rev. B 98, 054423 (2018).
[2] A. Sethi, J. E. Slimak, T. Kolodiazhnyi, and S. L. Cooper, Phys. Rev. Lett. 122, 177601.