Structural Disorder, Polarisation and the Normal to Relaxor Ferroelectric Transition in BaTiO3Based Perovskites

2010 ◽  
Vol 402 (1) ◽  
pp. 3-9 ◽  
Author(s):  
Y. Liu ◽  
R. L. Withers
Keyword(s):  
Structural Disorder ◽  
Relaxor Ferroelectric ◽  
Ferroelectric Transition

Local atomic structure of relaxor ferroelectric solids studied by pulsed neutron scattering

1994 ◽  
Vol 52 ◽  
pp. 554-555
Author(s):  
T. Egami ◽  
H. D. Rosenfeld ◽  
S. Teslic
Keyword(s):  
Neutron Scattering ◽  
Atomic Structure ◽  
Argonne National Laboratory ◽  
Relaxor Ferroelectrics ◽  
Relaxor Ferroelectric ◽  
Crystallographic Structure ◽  
Chemical Inhomogeneity ◽  
Distribution Analysis ◽  
Ferroelectric Transition ◽  
Pulsed Neutron

Relaxor ferroelectrics, such as Pb(Mg1/3Nb2/3)O3 (PMN) or (Pb·88La ·12)(Zr·65Ti·35)O3 (PLZT), show diffuse ferroelectric transition which depends upon frequency of the a.c. field. In spite of their wide use in various applications details of their atomic structure and the mechanism of relaxor ferroelectric transition are not sufficiently understood. While their crystallographic structure is cubic perovskite, ABO3, their thermal factors (apparent amplitude of thermal vibration) is quite large, suggesting local displacive disorder due to heterovalent ion mixing. Electron microscopy suggests nano-scale structural as well as chemical inhomogeneity.We have studied the atomic structure of these solids by pulsed neutron scattering using the atomic pair-distribution analysis. The measurements were made at the Intense Pulsed Neutron Source (IPNS) of Argonne National Laboratory. Pulsed neutrons are produced by a pulsed proton beam accelerated to 750 MeV hitting a uranium target at a rate of 30 Hz. Even after moderation by a liquid methane moderator high flux of epithermal neutrons with energies ranging up to few eV’s remain.

The spontaneous relaxor‐ferroelectric transition of Pb(Sc0.5Ta0.5)O3

1993 ◽  
Vol 74 (8) ◽  
pp. 5129-5134 ◽  
Author(s):  
F. Chu ◽  
N. Setter ◽  
A. K. Tagantsev
Keyword(s):  
Relaxor Ferroelectric ◽  
Ferroelectric Transition

Structural changes of relaxor ferroelectric Sr0.52Ba0.48Nb2O6(SBN52) on quenching and reheating

2017 ◽  
Vol 73 (5) ◽  
pp. 820-826 ◽  
Author(s):  
Heribert A. Graetsch
Keyword(s):  
Structural Changes ◽  
Ferroelectric Properties ◽  
Structural Disorder ◽  
Relaxor Ferroelectric ◽  
Mixed Crystals ◽  
Slow Cooling ◽  
Cation Sites ◽  
Large Cation

Quenching of Sr0.52Ba0.48Nb2O6(SBN52) from temperatures above 700°C causes small modifications in the strontium distribution over the large cation sites (Me1 and Me2), changed off-centre shifts of the Nb atoms and slightly increased modulation amplitudes. The higher disorder of cation incorporation can explain the enhanced ferroelectric properties. The quenched structural disorder can be healed by reheating followed by slow cooling. A change of the modulation dimension on quenching such as for CaxBa1−xNb2O6(CBN) mixed crystals was not observed.

High-throughput synthesis and electrical properties of BNT–BT–KNN lead-free piezoelectric ceramics

2020 ◽  
Vol 8 (11) ◽  
pp. 3655-3662 ◽  
Author(s):  
Guanhua Song ◽  
Zhibin Liu ◽  
Faqiang Zhang ◽  
Feng Liu ◽  
Yan Gu ◽  
...  
Keyword(s):  
Electrical Properties ◽  
High Throughput ◽  
High Strain ◽  
Piezoelectric Ceramics ◽  
Relaxor Ferroelectric ◽  
Lead Free ◽  
Ferroelectric Transition ◽  
High Throughput Method

Property diagrams of BNT–BT–KNN ceramics were obtained through a high-throughput method and the rhombohedral–relaxor ferroelectric transition led to high strain.

A Novel Mechanism for Relaxor-Ferroelectric Transition in PLZT(8/65/35)

2009 ◽  
Vol 92 (9) ◽  
pp. 2029-2032 ◽  
Author(s):  
Anickattu Somasekharan Divya ◽  
Viswanathan Kumar
Keyword(s):  
Relaxor Ferroelectric ◽  
Ferroelectric Transition

Measurement and Reduction of Radiation Damage in Frozen Hydrated Crystalline Specimens

1978 ◽  
Vol 36 (3) ◽  
pp. 70-77 ◽  
Author(s):  
R.M. Glaeser ◽  
S.B. Hayward
Keyword(s):  
Diffraction Pattern ◽  
Structural Information ◽  
Structural Disorder ◽  
Structural Features ◽  
Biological Macromolecules ◽  
Diffraction Intensity ◽  
Object Structure ◽  
Specimen Material ◽  
Unit Cells ◽  
Identical Unit

Highly ordered or crystalline biological macromolecules become severely damaged and structurally disordered after a brief electron exposure. Evidence that damage and structural disorder are occurring is clearly given by the fading and eventual disappearance of the specimen's electron diffraction pattern. The fading and disappearance of sharp diffraction spots implies a corresponding disappearance of periodic structural features in the specimen. By the same token, there is a oneto- one correspondence between the disappearance of the crystalline diffraction pattern and the disappearance of reproducible structural information that can be observed in the images of identical unit cells of the object structure. The electron exposures that result in a significant decrease in the diffraction intensity will depend somewhat upon the resolution (Bragg spacing) involved, and can vary considerably with the chemical makeup and composition of the specimen material.

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