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Spin-charge-lattice coupling in YBaCuFeO5: Optical properties and first-principles calculations.

ABSTRACT: We combined spectroscopic ellipsometry, Raman scattering spectroscopy, and first-principles calculations to explore the optical properties of YBaCuFeO5 single crystals. Measuring the optical absorption spectrum of YBaCuFeO5 at room temperature revealed a direct optical band gap at approximately 1.41 eV and five bands near 1.69, 2.47, 3.16, 4.26, and 5.54 eV. Based on first-principles calculations, the observed optical excitations were appropriately assigned. Analysis of the temperature dependence of the band gap indicated anomalies in antiferromagnetic phase transition at 455 and 175 K. Additionally, a hardening in the frequency of the Eg phonon mode was observed at 175 K. The value of the spin-phonon coupling constant was 15.7 mRy/Å2. These results suggest a complex nature of spin-charge-lattice interactions in YBaCuFeO5.

SUBMITTER: Chen HW

PROVIDER: S-EPMC6397168 | biostudies-literature | 2019 Mar

REPOSITORIES: biostudies-literature

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Spin-charge-lattice coupling in YBaCuFeO5: Optical properties and first-principles calculations.

Chen H W HW Chen Y-W YW Kuo J-L JL Lai Y C YC Chou F C FC Du C H CH Liu H L HL

Scientific reports 20190301 1

We combined spectroscopic ellipsometry, Raman scattering spectroscopy, and first-principles calculations to explore the optical properties of YBaCuFeO5 single crystals. Measuring the optical absorption spectrum of YBaCuFeO5 at room temperature revealed a direct optical band gap at approximately 1.41 eV and five bands near 1.69, 2.47, 3.16, 4.26, and 5.54 eV. Based on first-principles calculations, the observed optical excitations were appropriately assigned. Analysis of the ...[more]

PMID: 30824718

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