Electric field effect of relaxor ferroelectric (1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 crystals near morphotropic phase boundary composition probed by Brillouin scattering

Self Cite

Indomethacin (IMC) is a medicine available in various countries worldwide. The longitudinal acoustic (LA) and transverse acoustic (TA) modes of liquid, glass, and γ-form crystalline IMC were studied by Brillouin scattering spectroscopy on the basis of the backward scattering and reflection-induced ΘA scattering geometies. Upon heating of glassy IMC, the elastic anomaly at the liquid–glass transition temperature Tg = 315 K was clearly observed. With further heating of the supercooled liquid state, crystallization and melting into an equilibrium liquid phase were also observed. The temperature dependence of the elastic constants of a γ-form IMC crystal was determined using the observed velocities of an LA and two TA modes below the melting temperature Tm = 433 K.

“…The spot size of the beam incident to the sample was less than 10 μm. The temperature dependence of elastic properties was measured using a heating/cooling stage (Linkam HTMS600) [7,8].…”

Section: Methodsmentioning

confidence: 99%

Liquid, glass, and crystalline indomethacin studied by Brillouin scattering

Shibata¹,

Kojima²

2018

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“…The coexistence of macrodomain and nanodomain states was also observed in the case of PMN-30PT single crystals. 29) However, just above E R-T = 3.2 kV=cm, an additional TA mode appears and two LA modes merge into a single LA mode that reflects the field-induced transition from rhombohedral to tetragonal phases.…”

Section: Effect Of Electric Fieldmentioning

confidence: 99%

Temperature evolution of central peaks and effect of electric field in relaxor ferroelectric 0.83Pb(Mg_1/3Nb_2/3)O₃–0.17PbTiO₃single crystals

Helal¹,

Aftabuzzaman²,

Svirskas³

et al. 2017

Relaxor ferroelectric 0.83Pb(Mg1/3Nb2/3)O3–0.17PbTiO3 (PMN–17PT) single crystals were studied by Brillouin scattering to investigate the role of polar nanoregions (PNRs) with intermediate random fields (RFs). Upon cooling, the central peak began to appear at the Burns temperature (TB) of ∼600 K, indicating the existence of polarization relaxations induced by PNRs. The fitting performed using the equation of stretched slowing down at the inverse relaxation time revealed that the slowing down of PNRs was suppressed in PMN–17PT compared with that in PMN–56PT owing to the increase in the strength of RFs. At room temperature, the splitting of the longitudinal acoustic mode at 1.6 kV/cm was observed owing to the coexistence of the macrodomain formed by the external electric field along the [100] axis and the nanodomains formed by RFs. The appearance of the transverse acoustic mode at 3.2 kV/cm indicates the field-induced rhombohedral-to-tetragonal phase.

“…Similar acoustic behaviors were also observer in other typical REFs. 38,[55][56][57][58] At the characteristic temperatures of PNRs, the elastic properties become very sensitive and show anomalies via the scattering of LA phonons by PNRs. 59) Therefore, the temperature dependence of FWHM of the LA mode, which is proportional to the sound attenuation, was measured in a wide temperature range between −70 and 500 °C as shown in Fig.…”

Section: Srmentioning

confidence: 99%

Electric field effect on elastic properties of uniaxial relaxor Sr_xBa₁₋_xNb₂O₆single crystals with strong random fields

Aftabuzzaman

Helal

Dec

et al. 2017

The elastic properties of uniaxial relaxor SrxBa1−xNb2O6 (x = 0.70, SBN70) single crystals with strong random fields (RFs) were studied by Brillouin scattering spectroscopy as functions of temperature and external electric field along the [001] direction. A remarkable diffuseness of a ferroelectric phase transition was observed both on zero field heating and zero field cooling. The analysis of elastic anomaly shows the stretched critical slowing down of polar nanoregions (PNRs). Under 3.0 kV/cm, a complete alignment of nanodomains and an enhancement of the long-range ferroelectric order were observed below the Curie temperature TC = 23 °C. The alignment of quasistatic PNRs above TC was also observed under a sufficiently strong electric field. In a field-dependent measurement, a mixed state consisting of field-induced macrodomains and nanodomains caused by RFs was observed at 3.4 kV/cm. This mixed state persisted up to 9.0 kV/cm due to the incomplete switching of nanodomains to the macro/single domain state.