Phonon Anharmonicity and Spin-Phonon Coupling in CrI 3 .

Luca Tomarchio Lorenzo Mosesso Salvatore MacisLoi T NguyenAntonio GrilliMartina Romani Mariangela Cestelli GuidiRobert J CavaStefano Lupi

Published in: Materials (Basel, Switzerland) (2023)

We report on the far-infrared, temperature-dependent optical properties of a CrI3 transition metal halide single crystal, a van der Waals ferromagnet (FM) with a Curie temperature of 61 K. In addition to the expected phonon modes determined by the crystalline symmetry, the optical reflectance and transmittance spectra of CrI3 single crystals show many other excitations as a function of temperature as a consequence of the combination of a strong lattice anharmonicity and spin-phonon coupling. This complex vibrational spectrum highlights the presence of entangled interactions among the different degrees of freedom in CrI3.

Keyphrases

room temperature
transition metal
density functional theory
ionic liquid
high resolution
molecular dynamics
single molecule
energy transfer
perovskite solar cells