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Updated: Feb 7, 2026

Resonance Raman Spectroscopy of Extreme Nanowires and Other 1D Systems
Published on: April 28, 2016
Phonon and magnon modes in preferentially oriented epitaxial α-Fe2O3 thin films investigated by Raman spectroscopy
N Kumar1, I A Milekhin2, Bhavana Gupta3
1Tomsk State University, 36 Lenin Ave., Tomsk, 634050, Russia. kumarphysics1975@gmail.com.
Abstract:
Polarization- and temperature-dependent Raman spectroscopy of epitaxial α-Fe2O3 films revealed anisotropic phonon-magnon dynamics and spin-phonon coupling. Resonant excitation at 2.33 eV selectively enhanced the E2u(LO) mode via a defect-mediated double-resonance process, while the first-order E1u(LO) phonon exhibited single-phonon scattering. Polarization-resolved Raman spectra showed systematic angular variations in intensity I(θ), frequency ω(θ), and linewidth Γ(θ), arising from symmetry-selective electron-phonon coupling and decay pathways in the trigonal D63d structure. Ag phonon modes followed cos2 θ behavior, confirming c-axis orientation, while Eg modes showed off-diagonal tensor coupling. Temperature studies across the Morin transition (TM) revealed renormalization of phonon frequency and linewidth and enhanced magnon intensity above TM due to spin canting, with low-energy Ag and Eg modes exhibited the most pronounced spin-phonon coupling.
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