Temperature dependent photoexcited carrier dynamics in multiferroic BiFeO{sub 3} film: A hidden phase transition

Journal Article · Mon Apr 14 00:00:00 EDT 2014 · Applied Physics Letters

DOI:https://doi.org/10.1063/1.4871689· OSTI ID:22262591

Zhang, Zeyu; Jin, Zuanming; Pan, Qunfeng; Xu, Yue; Lin, Xian; Ma, Guohong ^[1]; Cheng, Zhenxiang ^[1]

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1. Department of Physics, Shanghai University, Shanghai 200444 (China)

The ultrafast carrier dynamics of the multiferroic BiFeO{sub 3} film in a broad temperature range is investigated using optical pump-probe spectroscopy. The photoexcited electrons release their energy with optical phonons emission through electron-phonon coupling in about 1 ps. The following intermediate process is identified as dynamical spin-lattice coupling in several picoseconds. Furthermore, the peak values of the optical reflectivity and the time constants of carrier relaxation channels show significant changes while the temperature varies from 137.5 K to around 195 K, this aligns with the previously reported hidden phase transition. Our study demonstrates that ultrafast spectroscopy is a sensitive method to look into the dynamical interactions among the on-site high-energy electrons accumulated in the p conduction band of Bi, coherent optical phonon, as well as the spin degree of freedom. These features play crucial roles in the characterization of phase transitions.

• OSTI ID: 22262591
• Journal Information: Applied Physics Letters, Journal Name: Applied Physics Letters Journal Issue: 15 Vol. 104; ISSN APPLAB; ISSN 0003-6951
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
CARRIERS
ELECTRON-PHONON COUPLING
EXCITED STATES
FILMS
PHASE TRANSFORMATIONS
REFLECTIVITY
SPIN
TEMPERATURE DEPENDENCE