Finite-temperature Raman spectroscopy of BaZrS3 explained by first principles theory*

We combine ab initio simulations and Raman scattering measurements to investigate BaZrS3, a highly polarizable yet lead-free chalcogenide Perovskite with strong optical response [1]. In particular, we focus on the temperature evolution of first- and second-order polarization-oriented (PO) and unpolarized Raman scattering. We present how anharmonic phonon theory coupled to ab initio simulations [2] can shed light on the underlying microscopic processes both quantitatively and qualitatively. We discuss the methodological challenges related to modeling similarly complex low-symmetry compounds at finite temperature such as correct treatment of long-range electrostatic interactions producing, e.g., LO/TO splitting. We conclude by giving remarks on other dielectric properties, e.g., infrared absorption, that can be obtained in the same framework in a numerically efficient way.

[1] S. Filippone, B. Zhao, S. Niu, N. Z. Koocher, D. Silevitch, I. Fina, J. M. Rondinelli, J. Ravichandran, and R. Jaramillo, Phys Rev Mater 4, 091601 (2020).

[2] N. Benshalom, G. Reuveni, R. Korobko, O. Yaffe, and O. Hellman, Phys Rev Mater 6, 033607 (2022).