TY - JOUR
T1 - Disorder origin of Raman scattering in perovskite single crystals
AU - Menahem, Matan
AU - Benshalom, Nimrod
AU - Asher, Maor
AU - Aharon, Sigalit
AU - Korobko, Roman
AU - Hellman, Olle
AU - Yaffe, Omer
N1 - Publisher Copyright:
© 2023 American Physical Society.
PY - 2023/4
Y1 - 2023/4
N2 - The anharmonic lattice dynamics of oxide and halide perovskites play a crucial role in their mechanical and optical properties. Raman spectroscopy is one of the key methods used to study these structural dynamics. However, despite decades of research, existing interpretations cannot explain the temperature dependence of the observed Raman spectra. We demonstrate the nonmonotonic evolution with temperature of the scattering intensity and present a model for second-order Raman scattering that accounts for this unique trend. By invoking a low-frequency anharmonic feature, we are able to reproduce the Raman spectral line shapes and integrated intensity temperature dependence. Numerical simulations support our interpretation of this low-frequency mode as a transition between two minima of a double-well potential surface. The model can be applied to other dynamically disordered crystal phases, providing a better understanding of the structural dynamics, leading to favorable electronic, optical, and mechanical properties in functional materials.
AB - The anharmonic lattice dynamics of oxide and halide perovskites play a crucial role in their mechanical and optical properties. Raman spectroscopy is one of the key methods used to study these structural dynamics. However, despite decades of research, existing interpretations cannot explain the temperature dependence of the observed Raman spectra. We demonstrate the nonmonotonic evolution with temperature of the scattering intensity and present a model for second-order Raman scattering that accounts for this unique trend. By invoking a low-frequency anharmonic feature, we are able to reproduce the Raman spectral line shapes and integrated intensity temperature dependence. Numerical simulations support our interpretation of this low-frequency mode as a transition between two minima of a double-well potential surface. The model can be applied to other dynamically disordered crystal phases, providing a better understanding of the structural dynamics, leading to favorable electronic, optical, and mechanical properties in functional materials.
UR - http://www.scopus.com/inward/record.url?scp=85153518263&partnerID=8YFLogxK
U2 - 10.1103/PhysRevMaterials.7.044602
DO - 10.1103/PhysRevMaterials.7.044602
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AN - SCOPUS:85153518263
SN - 2475-9953
VL - 7
JO - Physical Review Materials
JF - Physical Review Materials
IS - 4
M1 - 044602
ER -