1. Surface Recombination in Ultra-Fast Carrier Dynamics of Perovskite Oxide La0.7Sr0.3MnO3 Thin Films
- Author
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Robbyn Trappen, Sobhit Singh, Chih-Yeh Huang, Alessandra Romero, Ghadendra Bhandari, Guerau Cabrera, Alan D. Bristow, Shalini Kumari, A. C. Garcia-Castro, Navid Mottaghi, Saeed Yousefi Sarraf, and Mikel B. Holcomb
- Subjects
Materials science ,Spin polarization ,General Engineering ,General Physics and Astronomy ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Molecular physics ,0104 chemical sciences ,Condensed Matter::Materials Science ,Ferromagnetism ,General Materials Science ,Density functional theory ,Thin film ,0210 nano-technology ,Spin (physics) ,Circular polarization ,Recombination ,Perovskite (structure) - Abstract
Aspects of the optoelectronic performance of thin-film ferromagnetic materials are evaluated for application in ultrafast devices. Dynamics of photocarriers and their associated spin polarization are measured using transient reflectivity (TR) measurements in cross linear and circular polarization configurations for La0.7Sr0.3MnO3 films with a range of thicknesses. Three spin-related recombination mechanisms have been observed for thicker films (thickness of d ≥ 20 nm) at different time regimes (τ), which are attributed to the electron–phonon recombination (τ 1 ns). Density functional theory (DFT+U) based first-principles calculations provide information about the nature of the optical transitions and their probabilities for the majority and the minority spin channels. These transitions are partly responsible for the aforementioned recombination mechanisms, identified through the compari...
- Published
- 2019