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Updated: Mar 23, 2026
10:40
High Resolution Phonon-assisted Quasi-resonance Fluorescence Spectroscopy
Published on: June 28, 2016
8.0K
Polarization-resolved Raman and infrared phonon modes of ludlamite
Roberto L Moreira1, Ricardo Scholz2, Ariete Righi1
1Departamento de Física, ICEx, Universidade Federal de Minas Gerais, 31270-901 Belo Horizonte, MG, Brazil.
Summary
This study investigated ludlamite crystal
Area of Science:
- Solid State Physics
- Crystallography
- Spectroscopy
Background:
- Ludlamite, a phosphate mineral, exhibits complex optical properties.
- Understanding its vibrational modes is crucial for material characterization.
Purpose of the Study:
- To comprehensively investigate the optical vibrational modes of natural monoclinic ludlamite.
- To analyze the influence of cation substitution on these modes.
Main Methods:
- Polarized Raman and infrared-reflectivity spectroscopies were employed.
- Spectra were collected on high-quality single crystals from Brazil.
- Analysis involved the Lorentz oscillator model for infrared dielectric functions.
Main Results:
- Most predicted Raman-active (18Ag, 18Bg) and infrared-active (18Au, 17Bu) phonon modes were identified.
- Two-mode behavior in cation lattice modes indicated Fe2+ substitution by Mg2+.
- Bands associated with hydrogenated phosphate species were also observed.
Conclusions:
- The study successfully identified and assigned most optical vibrational modes of ludlamite.
- Cation substitution and hydrogenated species influence the vibrational spectra.
- Dielectric functions and constants align with theoretical expectations for ludlamite.
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