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Owada, Kenji*; Tsukada, Shinya*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro*; Owa, Hidehiro*; Yasuda, Naohiko*; Terauchi, Hikaru*
Physical Review B, 98(5), p.054106_1 - 054106_10, 2018/08
Times Cited Count:4 Percentile:18.32(Materials Science, Multidisciplinary)Owada, Kenji; Fukuda, Tatsuo; Mizuki, Junichiro; Hirota, Kazuma*; Terauchi, Hikaru*; Tsutsui, Satoshi*; Baron, A. Q. R.*; Owa, Hidehiro*; Yasuda, Naohiko*
Journal of the Korean Physical Society, 59(3), p.2509 - 2514, 2011/09
Times Cited Count:2 Percentile:19.62(Physics, Multidisciplinary)Pb(InNb
)O
(PIN) can be antiferroelectric (AFE), ferroelectric (FE) or a relaxor depending upon the perovskite B-site randomness. Orderd PIN (O-PIN, without B-site randomness) is supposed to be an ideal system of lead-based complex perovskite Pb(B'B'')O
and expected to give us a clear picture of the AFE/relaxor nature of the ground state by the B-site randomness. We studied the dynamics of O-PIN by inelastic X-ray scattering. The quasielastic (QE) scattering shows the critical slowing down and the transverse acoustic (TA) mode shows the softening towards
. On the other hand, the transverse optic (TO) mode shows the softening toward low temperature with no clear anomaly at
. These results represent that the antiferroelectric (AFE) phase transition is associated with the TA and the origin of the QE scattering, while ferroelectric correlation does exist behind the AFE ordering. The effect of B-site randomness is finally discussed on the basis of the results.
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro; Owa, Hidehiro*; Yasuda, Naohiko*
Transactions of the Materials Research Society of Japan, 34(1), p.19 - 22, 2009/03
Pb(InNb
)O
(PIN) can be antiferroelectric (AFE), ferroelectric (FE) or a relaxor depending upon the perovskite B-site randomness. This is characterized by measurements of dielectric response, which shows behavior that is usually clearly in one of those three classes. In contrast, X-ray scattering studies suggest the presence of AFE correlation in the relaxor state and FE in AFE state. Weak phonon softening at zone boundary in relaxor state shows that the AFE correlation intrinsically exists in PIN, as does the corresponding elastic scattering at (
/2
/2 0), while weak diffuse scattering around 333 Bragg reflection appears in AFE state suggesting FE correlation. These results will support our previous speculation that the AFE and FE correlations coexist in PIN (K. Owada
., Phys, Rev. B
094136 (2008)). Such a coexistence or competition is widely seen in the perovskite relaxor and the coexistence of FE and AFE correlations is essential for generating relaxor state.
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro; Owa, Hidehiro*; Yasuda, Naohiko*
Physical Review B, 77(9), p.094136_1 - 094136_8, 2008/03
Times Cited Count:19 Percentile:60.26(Materials Science, Multidisciplinary)Antiferroelectric (AFE), ferroelectric (FE) or relaxor states can appear in Pb(InNb
)O
(PIN) depending upon the perovskite B-site randomness. We studied the effects of this randomness on the dynamics of PIN by high resolution inelastic X-ray scattering using ordered PIN (AFE) and disordered PIN (relaxor) single crystals. We have found a clear softening of a transverse optic mode at the
point in both the samples, indicating a robust and intrinsic ferroelectric instability regardless of the actual ground state. We interpret that AFE is stabilized only when In and Nb ions are spatially ordered enough to overwhelm the FE instability. As the B-site randomness becomes larger, AFE is suppressed and the hidden FE state starts appearing. Ultimately, the randomness begins to predominate over the development of FE regions and blocks a long range FE order, which we believe yields polar nanoregions resulting in relaxor behaviors.
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Owa, Hidehiro*; Yasuda, Naohiko*
Journal of the Physical Society of Japan, 75(2), p.024606_1 - 024606_6, 2006/12
Times Cited Count:6 Percentile:41.34(Physics, Multidisciplinary)Structural properties of Pb(In
Nb
)O
(PIN) single crystals at room temperature (RT) were investigated by X-ray and neutron scattering techniques, taking much account of the difference in the penetration depth and spatial resolution of X-rays and those of neutrons. A strong diffuse scattering was observed by X-ray while h/4, k/4, 0 superlattice reflections were found by neutron, indicating a relaxor state in the outer-layer of the crystal and an antiferroelectric (AFE) state in the bulk. The phonon dispersion was measured for the first time for the PIN series. Two transverse optic (TO1 and TO2) modes were clarified near the zone center though neither water-fall behavior nor folding of phonon branches was confirmed. We have thus concluded that a major part of the
PIN crystal at RT is ferroelectric (FE). These results imply that the
-site chemical ordering, i.e. inhomogeneity, which controls the structural properties of PIN, is unevenly distributed throughout the crystal. We speculate that small AFE grains coexist with the FE matrix while the outer-layer is in a relaxor state in the
PIN.
Owada, Kenji; Hirota, Kazuma*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Terauchi, Hikaru*; Yasuda, Naohiko*; Owa, Hidehiro*; Mizuki, Junichiro
no journal, ,
no abstracts in English
Owada, Kenji; Hirota, Kazuma*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A.*; Mizuki, Junichiro; Terauchi, Hikaru*; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
Pb(InNb
)O
(PIN) varies among antiferroelectric (AFE), ferroelectric (FE) and relaxor states depending upon the perovskite B-site randomness. We studied the effects of this randomness on the dynamics of PIN by high resolution inelastic X-ray scattering using ordered PIN (AFE) and disordered PIN (relaxor) single crystals. We have found a clear softening of a transverse optic mode at the
point in both the samples, indicating a robust and intrinsic ferroelectric instability regardless of the actual ground state. We interpret that AFE is stabilized only when In and Nb ions are spatially ordered enough to overwhelm the FE instability. As the B-site randomness becomes larger, AFE is suppressed and the FE ground state starts appearing. Ultimately, the randomness competes with the development of FE regions and blocks a long range FE order, which we believe yields polar nanoregions resulting in relaxor behaviors.
Owada, Kenji; Hirota, Kazuma*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro; Terauchi, Hikaru*; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
no abstracts in English
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
Pb(InNb
)O
(PIN) varies among antiferroelectric (AFE), ferroelectric (FE) and relaxor states depending upon the perovskite B-site randomness. We studied the effects of this randomness on the dynamics of PIN by high resolution inelastic X-ray scattering using ordered PIN (AFE) and disordered PIN (relaxor) single crystals. We have found a clear softening of a transverse optic mode at the
point in both the samples, indicating a robust and intrinsic ferroelectric instability regardless of the actual ground state. We interpret that AFE is stabilized only when In and Nb ions are spatially ordered enough to overwhelm the FE instability. As the B-site randomness becomes larger, AFE is suppressed and the FE ground state starts appearing. Ultimately, the randomness competes with the development of FE regions and blocks a long range FE order, which we believe yields polar nanoregions resulting in relaxor behaviors.
Oshima, Akihiro*; Shiraki, Fumiya*; Takasawa, Yuya*; Fujita, Hajime*; Yoshikawa, Taeko*; Tatsumi, Takahiro*; Tsubokura, Hidehiro*; Takahashi, Tomohiro*; Gowa, Tomoko*; Sakaue, Kazuyuki*; et al.
no journal, ,
no abstracts in English
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Fukuda, Tatsuo; Tsutsui, Satoshi*; Baron, A. Q. R.*; Mizuki, Junichiro; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
no abstracts in English
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
no abstracts in English
Owada, Kenji; Hirota, Kazuma*; Terauchi, Hikaru*; Owa, Hidehiro*; Yasuda, Naohiko*
no journal, ,
no abstracts in English