scholarly journals Mapping bias-induced phase stability and random fields in relaxor ferroelectrics

2009 ◽  
Vol 95 (9) ◽  
pp. 092904 ◽  
Author(s):  
B. J. Rodriguez ◽  
S. Jesse ◽  
A. A. Bokov ◽  
Z.-G. Ye ◽  
S. V. Kalinin
Keyword(s):  
Phase Stability ◽  
Random Fields ◽  
Relaxor Ferroelectrics ◽  
Mapping Bias

Angle-resolved polarized Raman scattering on relaxor ferroelectrics with intermediate random fields

2018 ◽  
Vol 57 (11S) ◽  
pp. 11UB08 ◽  
Author(s):  
Md Al Helal ◽  
Shinya Tsukada ◽  
Šarūnus Svirskas ◽  
Jūras Banys ◽  
Seiji Kojima
Keyword(s):  
Raman Scattering ◽  
Random Fields ◽  
Relaxor Ferroelectrics ◽  
Polarized Raman

Mesoscale origin of dielectric relaxation with superior electrostrictive strain in bismuth ferrite-based ceramics

2020 ◽  
Vol 7 (11) ◽  
pp. 3011-3020 ◽  
Author(s):  
Ting Zheng ◽  
Jiagang Wu
Keyword(s):  
Dielectric Relaxation ◽  
Random Fields ◽  
Bismuth Ferrite ◽  
Relaxor Ferroelectrics ◽  
Nano Structures ◽  
Domain Configuration

A strategy to optimize electrostrictive strain in BFO-based relaxor ferroelectrics was proposed. By operating the domain configuration via ion engineering the B-site order/disorder and random fields, two kinds of polar nano-structures can be formed.

RANDOM FIELDS IN RELAXOR FERROELECTRICS — A JUBILEE REVIEW

2012 ◽  
Vol 02 (02) ◽  
pp. 1241001 ◽  
Author(s):  
WOLFGANG KLEEMANN
Keyword(s):  
Random Fields ◽  
Characteristic Temperature ◽  
Parent Phase ◽  
Frequency Dispersion ◽  
Relaxor Ferroelectrics ◽  
Relaxor Ferroelectric ◽  
Temperature Phase ◽  
Field Equations ◽  
Apparent Lack ◽  
Polar Order

Substitutional charge disorder as in PbMg1/3Nb2/3O3 , structural cation vacancies as in Sr x Ba 1-x Nb 2 O 6 and isovalent substitution of off-centered cations as in BaTi 1-x Sn x O 3 and BaTi 1-x Zr x O 3 give rise to quenched electric random-fields (RF s ), which we proposed to be at the origin of the peculiar behavior of relaxor ferroelectrics 20 years ago. These are, e.g. a strong frequency dispersion of the dielectric response and an apparent lack of macroscopic symmetry breaking in the low temperature phase. Both are related to mesoscopic RF-driven phase transitions, which give rise to irregularly shaped quasi-stable polar nanoregions below the characteristic temperature T*, but above the global transition temperature Tc. Their co-existence with the paraelectric parent phase can be modeled by time-dependent field equations under the control of quenched RF s and stress-free strain (in the case of order parameter dimension n ≥ 2). Transitions into global polar order at Tc may occur in uniaxial relaxors as observed on the uniaxial relaxor ferroelectric Sr0.8Ba0.2Nb2O6 and come close to RF Ising model criticality. Re-entrant relaxor transitions as observed in solid solutions of Ba2Pr0.6Nd0.4(FeNb4)O15 are proposed to evidence the coexistence of distinct normal and relaxor ferroelectric phases within the framework of percolation theory.

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.

Tuning the phase stability and surface HER activity of 1T′-MoS2 by covalent chemical functionalization

2020 ◽  
Vol 8 (44) ◽  
pp. 15852-15859
Author(s):  
Jiu Chen ◽  
Fuhua Li ◽  
Yurong Tang ◽  
Qing Tang
Keyword(s):  
Phase Stability ◽  
Chemical Functionalization ◽  
The Stability

Chemical functionalization can significantly improve the stability of meta-stable 1T′-MoS2 and tune the surface HER activity.

Comparison of random field strengths in (1-x)SrTiO3-xBiFeO3 and (1-x)SrTiO3-xBaTiO3 relaxor ferroelectrics by means of acoustic emission

2020 ◽  
Vol 92 (2) ◽  
pp. 20401
Author(s):  
Evgeniy Dul'kin ◽  
Michael Roth
Keyword(s):  
Acoustic Emission ◽  
Random Field ◽  
Electric Fields ◽  
Bias Field ◽  
Relaxor Ferroelectrics ◽  
External Bias ◽  
Field Strengths

In relaxor (1-x)SrTiO3-xBiFeO3 ferroelectrics ceramics (x = 0.2, 0.3 and 0.4) both intermediate temperatures and Burns temperatures were successfully detected and their behavior were investigated in dependence on an external bias field using an acoustic emission. All these temperatures exhibit a non-trivial behavior, i.e. attain the minima at some threshold fields as a bias field enhances. It is established that the threshold fields decrease as x increases in (1-x)SrTiO3-xBiFeO3, as it previously observed in (1-x)SrTiO3-xBaTiO3 (E. Dul'kin, J. Zhai, M. Roth, Phys. Status Solidi B 252, 2079 (2015)). Based on the data of the threshold fields the mechanisms of arising of random electric fields are discussed and their strengths are compared in both these relaxor ferroelectrics.

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