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Updated: Feb 20, 2026
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Characterization of Nanocrystal Size Distribution using Raman Spectroscopy with a Multi-particle Phonon Confinement Model
Published on: August 22, 2015
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A comparative Raman study between PrMnO 3, NdMnO 3, TbMnO 3 and DyMnO 3
Sabeur Mansouri1, Serge Jandl2, Alexander Mukhin3
1Université de Sherbrooke, Regroupement Québécois sur les Matériaux de Pointe et Institut Quantique, Département de Physique, Sherbrooke, J1K 2R1, Canada. saber.mansouri@usherbrooke.ca.
Scientific Reports
|October 25, 2017
Summary
This study reveals anomalous phonon shifts in rare-earth manganites near their Néel transition. These shifts, linked to orbital-spin-phonon coupling and bond length changes, offer insights into multiferroicity.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Spectroscopy
Background:
- Rare-earth manganites (RMnO3) exhibit complex magnetic and electronic properties.
- Multiferroic materials display coupled ferroic orders, making them promising for novel devices.
- Raman spectroscopy is a powerful tool for probing lattice dynamics and phase transitions.
Purpose of the Study:
- To investigate the temperature and magnetic field dependence of phonon behavior in non-multiferroic (PrMnO3, NdMnO3) and multiferroic (TbMnO3, DyMnO3) compounds.
- To elucidate the microscopic mechanisms behind observed phonon anomalies near the magnetic ordering temperature (Néel transition).
- To understand the role of spin-phonon and orbital-phonon coupling in these materials.
Main Methods:
- Detailed temperature-dependent Raman spectroscopy.
- Magnetic field-dependent Raman spectroscopy.
- Analysis of phonon frequency shifts and their correlation with magnetic transitions.
Main Results:
- All studied RMnO3 compounds exhibited anomalous phonon shifts near the Néel transition (TN).
- Frequency softenings in PrMnO3 and NdMnO3 were attributed to orbital-spin-phonon coupling.
- In TbMnO3 and DyMnO3, weaker shifts were linked to Mn-O bond length expansion, with TbMnO3 showing magnetic field-dependent shifts attributed to oxygen rearrangements.
Conclusions:
- Phonon anomalies near TN are characteristic of RMnO3 systems, with distinct mechanisms in multiferroic and non-multiferroic compounds.
- Orbital-spin-phonon coupling significantly influences lattice dynamics in PrMnO3 and NdMnO3.
- Magnetic field-induced oxygen rearrangements are crucial for understanding the multiferroicity in TbMnO3 and DyMnO3.
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