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Excitonic Hamiltonians for Calculating Optical Absorption Spectra and Optoelectronic Properties of Molecular Aggregates and Solids
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Spin-charge-lattice coupling in YBaCuFeO5: Optical properties and first-principles calculations
H W Chen1, Y-W Chen2, J-L Kuo2
1Department of Physics, National Taiwan Normal University, Taipei, 11677, Taiwan.
Scientific Reports
|March 3, 2019
Summary
This study investigates YBaCuFeO5 single crystals, revealing optical band gaps and excitations. Anomalies in antiferromagnetic transitions and phonon modes suggest complex spin-charge-lattice interactions.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Solid-State Chemistry
Background:
- YBaCuFeO5 is a multiferroic material with complex magnetic and electronic properties.
- Understanding its optical properties is crucial for exploring spin-charge-lattice coupling.
Purpose of the Study:
- To investigate the optical properties of YBaCuFeO5 single crystals.
- To correlate optical findings with magnetic phase transitions and phonon behavior.
Main Methods:
- Spectroscopic ellipsometry and Raman scattering spectroscopy were employed.
- First-principles calculations were used to assign optical excitations.
Main Results:
- A direct optical band gap of ~1.41 eV and several absorption bands were identified.
- Anomalies in band gap temperature dependence at 455 K and 175 K indicate antiferromagnetic transitions.
- A hardening of the Eg phonon mode at 175 K and a spin-phonon coupling constant of 15.7 mRy/Ų were determined.
Conclusions:
- The study reveals intricate spin-charge-lattice interactions in YBaCuFeO5.
- Observed anomalies are linked to magnetic phase transitions and phonon behavior, highlighting material complexity.
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