1. Fig. 1 Phonon dispersion along Q = [2 + H, −2 + H, 0] (L = 0 ± 0
Fig. 1 Phonon dispersion along Q = [2 + H, −2 + H, 0] (L = 0 ± 0.05) in PMN-30%PT comparing temperature and poling effects.
Phonon dispersion along Q = [2 + H, −2 + H, 0] (L = 0 ± 0.05) in PMN-30%PT comparing temperature and poling effects. (A) Unpoled crystal measured above TC at 488 K showing a single TA mode. (B) Unpoled crystal measured below TC at 300 K showing splitting of the TA phonon. (C and D) Sketches of the diffuse elastic scattering around (HH0) reflections in the (HK0) plane, above and below TC (7, 28). (E) Inelastic scattering intensity map at the energy of the lower branch of the split TA phonon (E = [2, 4] meV) near the (2, −2, 0) reflection in the (HK0) plane. (F) [100]-poled PMN-30%PT showing a marked softening of the lower section of the TA branch (left) and an increase in the splitting of the TA mode from 1.5 to 2 meV (right). Data points overlaying the images of the TA phonon [center in (A), (B), and (F)] are peak positions from fits to the data, and the white lines running through these points are guides to the eye. (G) Confirmation of features in the (1, −1, 0) zone for the same direction, Q = [1 + H, −1 + H, 0]. The transverse optic (TO) and upper TA branch appear relatively weaker in the (1, −1, 0) zone, but the same features appear. All measurements were made on the time-of-flight angular-range chopper spectrometer (ARCS) at the Spallation Neutron Source, Oak Ridge National Laboratory.
Michael E. Manley et al. Sci Adv 2016;2:e
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