TY - JOUR
T1 - Relaxor-ferroelectric crossover in (B i1/2 K1/2)Ti O3
T2 - Origin of the spontaneous phase transition and the effect of an applied external field
AU - Hagiwara, Manabu
AU - Ehara, Yoshitaka
AU - Novak, Nikola
AU - Khansur, Neamul H.
AU - Ayrikyan, Azatuhi
AU - Webber, Kyle G.
AU - Fujihara, Shinobu
N1 - Publisher Copyright:
© 2017 American Physical Society.
Copyright:
Copyright 2019 Elsevier B.V., All rights reserved.
PY - 2017/7/6
Y1 - 2017/7/6
N2 - The temperature evolution of polar order in an A-site complex perovskite (Bi1/2K1/2)TiO3 (BKT) has been investigated by measurements of dielectric permittivity, depolarization current, and stress-stain curves at elevated temperatures. Upon cooling from high temperatures, BKT first enters a relaxor state and then spontaneously transforms into a ferroelectric state. The analyses of temperature and frequency dependence of permittivity have revealed that polar nanoregions of the relaxor phase appear at temperatures higher than 560C, and also that their freezing at 296C triggers the spontaneous relaxor-ferroelectric transition. We discuss the key factors determining the development of long-range polar order in A-site complex perovskites through a comparison with the relaxor (Bi1/2Na1/2)TiO3. We also show that application of biasing electric fields and compressive stresses to BKT favors its ferroelectric phase, resulting in a significant shift of the relaxor-ferroelectric transition temperature towards higher temperatures. Based on the obtained results, electric field-temperature and stress-temperature phase diagrams are firstly determined for BKT.
AB - The temperature evolution of polar order in an A-site complex perovskite (Bi1/2K1/2)TiO3 (BKT) has been investigated by measurements of dielectric permittivity, depolarization current, and stress-stain curves at elevated temperatures. Upon cooling from high temperatures, BKT first enters a relaxor state and then spontaneously transforms into a ferroelectric state. The analyses of temperature and frequency dependence of permittivity have revealed that polar nanoregions of the relaxor phase appear at temperatures higher than 560C, and also that their freezing at 296C triggers the spontaneous relaxor-ferroelectric transition. We discuss the key factors determining the development of long-range polar order in A-site complex perovskites through a comparison with the relaxor (Bi1/2Na1/2)TiO3. We also show that application of biasing electric fields and compressive stresses to BKT favors its ferroelectric phase, resulting in a significant shift of the relaxor-ferroelectric transition temperature towards higher temperatures. Based on the obtained results, electric field-temperature and stress-temperature phase diagrams are firstly determined for BKT.
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U2 - 10.1103/PhysRevB.96.014103
DO - 10.1103/PhysRevB.96.014103
M3 - Article
AN - SCOPUS:85026437343
VL - 96
JO - Physical Review B-Condensed Matter
JF - Physical Review B-Condensed Matter
SN - 2469-9950
IS - 1
M1 - 014103
ER -