skip to main content

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

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.
Authors:
; ; ; ; ;  [1] ;  [1] ;  [2]
  1. Department of Physics, Shanghai University, Shanghai 200444 (China)
  2. (Australia)
Publication Date:
OSTI Identifier:
22262591
Resource Type:
Journal Article
Resource Relation:
Journal Name: Applied Physics Letters; Journal Volume: 104; Journal Issue: 15; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; CARRIERS; ELECTRON-PHONON COUPLING; EXCITED STATES; FILMS; PHASE TRANSFORMATIONS; REFLECTIVITY; SPIN; TEMPERATURE DEPENDENCE