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Polarized Raman spectra of hematite and assignment of external modes
Author(s) -
Marshall Craig P.,
Dufresne William J.B.,
Rufledt Carson J.
Publication year - 2020
Publication title -
journal of raman spectroscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.748
H-Index - 110
eISSN - 1097-4555
pISSN - 0377-0486
DOI - 10.1002/jrs.5824
Subject(s) - raman spectroscopy , hematite , phonon , raman scattering , polarization (electrochemistry) , crystal (programming language) , coherent anti stokes raman spectroscopy , spectral line , chemistry , condensed matter physics , molecular physics , physics , materials science , optics , mineralogy , quantum mechanics , computer science , programming language
Notwithstanding the significant practical importance of hematite, α‐Fe 2 O 3 , the complete assignment and understanding of the Raman spectrum acquired on this crystalline solid are uncertain. Above all, only one of the two external E g phonons arising from the Γ point has been resolved and hence assigned. It is well known that the E g mode at 294 cm −1 has been attributed to one of the two external phonons arising from the Γ point. To this end, we have undertaken studies to examine the polarized Raman scattering on a pure single crystal to gain a better understanding and assignment of phonons arising from the Γ point in the Raman spectrum of hematite. Here, we resolve and assign the previously unidentified external E g phonon at 245 cm −1 and, additionally, confirm that the band at 294 cm −1 is an external E g phonon, in the first‐order Raman spectrum of hematite. Further, our polarized Raman spectra display interesting polarization behavior of the 2LO mode at 1320 cm −1 , where this band is only Raman active in e i || e s polarization configurations.