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- Chen, F., et al.
(författare)
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Reply to "comment on 'Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO3 ' "
- 2018
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Ingår i: Physical Review B. - 2469-9950. ; 97:22
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Tidskriftsartikel (refereegranskat)abstract
- In this reply to S. Durbin's comment on our original paper "Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO3," we concur that his final equations 8 and 9 more accurately describe the change in diffracted intensity as a function of Ti displacement. We also provide an alternative derivation based on an ensemble average over unit cells. The conclusions of the paper are unaffected by this correction.
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- Chen, F., et al.
(författare)
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Ultrafast terahertz-field-driven ionic response in ferroelectric BaTiO3
- 2016
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Ingår i: Physical Review B. - 1098-0121. ; 94:18
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Tidskriftsartikel (refereegranskat)abstract
- The dynamical processes associated with electric field manipulation of the polarization in a ferroelectric remain largely unknown but fundamentally determine the speed and functionality of ferroelectric materials and devices. Here we apply subpicosecond duration, single-cycle terahertz pulses as an ultrafast electric field bias to prototypical BaTiO3 ferroelectric thin films with the atomic-scale response probed by femtosecond x-ray-scattering techniques. We show that electric fields applied perpendicular to the ferroelectric polarization drive large-amplitude displacements of the titanium atoms along the ferroelectric polarization axis, comparable to that of the built-in displacements associated with the intrinsic polarization and incoherent across unit cells. This effect is associated with a dynamic rotation of the ferroelectric polarization switching on and then off on picosecond time scales. These transient polarization modulations are followed by long-lived vibrational heating effects driven by resonant excitation of the ferroelectric soft mode, as reflected in changes in the c-axis tetragonality. The ultrafast structural characterization described here enables a direct comparison with first-principles-based molecular-dynamics simulations, with good agreement obtained.
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- Miniotas, A, et al.
(författare)
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Misfit strain induced lattice distortions in heteroepitaxially grown LaxCa1-xMnO3 thin films studied by extended x-ray absorption fine structure and high-resolution x-ray diffraction
- 2001
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Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 89:4, s. 2134-2137
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Tidskriftsartikel (refereegranskat)abstract
- Mn-O and Mn-Mn interatomic distances were determined in LaxCa1-xMnO3 films grown heteroepitaxially on single crystal SrTiO3 and LaAlO3 substrates by molecular beam epitaxy. Mn-O bond lengths were found to be fixed at similar to1.975 Angstrom for both types of substrates, while the Mn-Mn distance was detected to be larger for films grown on SrTiO3 substrates than for films grown on LaAlO3. The deviation of Mn-Mn interatomic distances, and subsequently Mn-O-Mn bond angles, in epitaxial LaxCa1-xMnO3 films is attributed to the misfit strain: compressive for LaAlO3 and tensile for SrTiO3 substrates. (C) 2001 American Institute of Physics.
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