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.

Local atomic structure of relaxor ferroelectric solids determined by pulsed neutron and x-ray scattering

1997 ◽  
Vol 199 (1) ◽  
pp. 103-113 ◽  
Author(s):  
T. Egami ◽  
S. Teslic ◽  
W. Dmowski ◽  
D. Viehland ◽  
S. Vakhrushev
Keyword(s):  
Atomic Structure ◽  
Relaxor Ferroelectric ◽  
Local Atomic Structure ◽  
X Ray ◽  
X Ray Scattering ◽  
Pulsed Neutron ◽  
Ray Scattering

scholarly journals Implications of acceptor doping in the polarization and electrocaloric response of 0.9Pb(Mg1/3Nb2/3)O3–0.1PbTiO3 relaxor ferroelectric ceramics

2021 ◽  
Vol 9 (9) ◽  
pp. 3204-3214
Author(s):  
Andraž Bradeško ◽  
Marko Vrabelj ◽  
Lovro Fulanović ◽  
Šarūnas Svirskas ◽  
Maksim Ivanov ◽  
...  
Keyword(s):  
Relaxor Ferroelectrics ◽  
Relaxor Ferroelectric ◽  
Ferroelectric Ceramics ◽  
Acceptor Doping ◽  
Defect Engineering ◽  
Relaxor Ferroelectric Ceramics

Defect engineering by acceptor doping affects the dipolar state in relaxor ferroelectrics, resulting in a tailored electrocaloric response.

Pulsed neutron scattering on molten Bi + BiI3 mixtures

1981 ◽  
Vol 83 (1) ◽  
pp. 35-38 ◽  
Author(s):  
Kazuhiko Ichikawa ◽  
Takaaki Matsumoto
Keyword(s):  
Neutron Scattering ◽  
Pulsed Neutron

Atomic Structure of PbZrO3 Determined by Pulsed Neutron Diffraction

1998 ◽  
Vol 54 (6) ◽  
pp. 750-765 ◽  
Author(s):  
S. Teslic ◽  
T. Egami
Keyword(s):  
Atomic Structure ◽  
Intermediate Phase ◽  
Function Analysis ◽  
Lead Zirconate ◽  
Neutron Powder Diffraction Data ◽  
Antiferroelectric Phase ◽  
Atomic Pair Distribution Function ◽  
Atomic Pair ◽  
Increasing Temperature ◽  
Pulsed Neutron

The atomic structure of lead zirconate, PbZrO3 (PZ), was studied using Rietveld refinement and atomic pair distribution function analysis of pulsed neutron powder diffraction data for the antiferroelectric, intermediate and paraelectric phases. The symmetry of PZ at T = 20 K in the antiferroelectric phase was determined to be Pbam. The structure was characterized by distortions of the ZrO6 octahedra which are smaller than in previous studies. Locally correlated displacements of Pb in the c direction develop with increasing temperature. The average magnitude was 0.06 Å at room temperature, 0.14 Å at T = 473 K and 0.20 Å in the intermediate phase at T = 508 K. The intermediate phase was characterized by in-plane antiferroelectric Pb displacements which produce 1\over 2{110} superlattice diffraction peaks. Above 473 K the local structure of PZ remains largely unchanged, in spite of the transitions in the long-range order from the antiferroelectric to the intermediate and to the paraelectric phases.

Comparison of Small-Angle Neutron Scattering of δ' Precipitation in an Al–Li Alloy at a High-Flux Reactor and at a Pulsed-Neutron Source

1997 ◽  
Vol 30 (5) ◽  
pp. 602-606 ◽  
Author(s):  
G. Albertini ◽  
F. Carsughi ◽  
R. Coppola ◽  
R. K. Heenan ◽  
M. Stefanon
Keyword(s):  
Neutron Scattering ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Size Distribution Function ◽  
Data Sets ◽  
Flux Reactor ◽  
Average Size ◽  
Pulsed Neutron ◽  
Pulsed Neutron Source ◽  
Good Agreement

Two different small-angle neutron scattering (SANS) facilities, the D11 camera at the Institut Laue–Langevin (ILL, Grenoble, France) and the LOQ time-of-flight diffractometer at the Rutherford Appleton Laboratory (RAL, Didcot, Oxon, England), were used in the investigations of δ′-Al3Li precipitation at 463 K in Al–Li 3% alloy. The results obtained from the steady-state reactor and from the pulsed source by using two different data-acquisition techniques and two different procedures for data analysis are compared. The SANS curves for the same set of samples investigated using the two different instruments are in good agreement within the experimental uncertainties. A check was also made on the metallurgically relevant quantities, namely the average size and the size-distribution function of the δ′ precipitates at the various stages of the ageing process, obtained from the two sets of SANS curves by applying the same numerical method. Good agreement was found between the results from the two data sets.

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