In this study, we present a comprehensive analysis of the Raman active phonon modes in orthorhombic LaInO3 based on a combination of polarization-angle resolved Raman spectroscopy and density functional theory calculations. By using backscattering from multiple crystallographic surface orientations and employing a full symmetry analysis, we identify and assign most of the Raman-active Γ-point phonons to their irreducible representations of the D2h point group. A multidimensional hyperspectral fitting procedure allows us to extract the relative Raman tensor elements from the angular dependence of the scattering intensities, even for strongly overlapping modes. First-principles calculations yield the phonon dispersion along high-symmetry directions, the phonon densities of states, and atomic displacement patterns, which are found to be in good agreement with the experimental mode frequencies.
@article{arxiv.2604.15156,
title = {Lattice dynamics and complete polarization analysis of Raman-active modes in LaInO$_3$},
author = {Jonas Rose and Hai Nguyen and Moritz Meißner and Zbigniew Galazka and Roland Gillen and Georg Hoffmann and Oliver Brandt and Manfred Ramsteiner and Markus R. Wagner and Hans Tornatzky},
journal= {arXiv preprint arXiv:2604.15156},
year = {2026}
}