Ultrafast anisotropic optical response and coherent acoustic phonon generation in polycrystalline BaTiO3-BiFeO3
Reviews and Highlights | Quantum Science | Molecular and Soft-matter | Ultrafast Nano-optics and Nanophotonics | Mineralogy and Geochemistry |
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Brenden Magill, Kyoung-Duck Park, Yuan Zhou, Anuj Chopra, Deepam Maurya, Shashank Priya, Markus Raschke, Alexey Belyanin, Christopher J. Stanton, and Giti Khodaparast
Energy Harvesting and Systems 3, 229 (2016).
DOI PDF
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We optically study the as-yet little explored multiferroic material, BaTiO3-BiFeO3 (BTO-BFO), that has demonstrated enhanced magnetic properties, a higher DC resistance in comparison to BFO, and improved magnetoelectric coupling. Our studies include: ultrafast time resolved differential reflection, optically induced birefringence, and second-harmonic nano-imaging of the ferroic order. We observe a strong sensitivity to pump/probe polarizations, photo-induced ferroelectric poling on a picosecond timescale, as well as the generation of photo-induced coherent acoustic phonons with a frequency of ~11 GHz. The second-harmonic generation nano-imaging reveals disordered but distinct ferroelectric domain order, percolating even across grain boundaries in the poly-crystalline thin film.