Kinetics of ferroelectric domains: Application of general approach to LiNbO3 and LiTaO3

2007 ◽  
pp. 199-210 ◽  
Author(s):  
Vladimir Ya. Shur
Keyword(s):  
Ferroelectric Domains ◽  
Kinetics Of

Kinetics of ferroelectric domains investigated by scanning force microscopy

2000 ◽  
Vol 61 (21) ◽  
pp. 14440-14447 ◽  
Author(s):  
V. Likodimos ◽  
M. Labardi ◽  
M. Allegrini
Keyword(s):  
Scanning Force Microscopy ◽  
Force Microscopy ◽  
Ferroelectric Domains ◽  
Scanning Force ◽  
Kinetics Of

IMPACT OF THE AMBIENT HUMIDITY ON THE KINETICS OF FORMATION OF FERROELECTRIC DOMAINS IN MONOCRYSTALLINE LiTaO3

2012 ◽  
Vol 11 (04) ◽  
pp. 1240013 ◽  
Author(s):  
BRICE GAUTIER ◽  
ANTOINE BRUGÈRE ◽  
SERGE GIDON
Keyword(s):  
Water Layer ◽  
Element Model ◽  
Active Role ◽  
Ferroelectric Material ◽  
Thermally Activated ◽  
Atomic Force ◽  
Ferroelectric Layer ◽  
Ferroelectric Domains ◽  
Kinetics Of Formation ◽  
Kinetics Of

In this communication, we study the role of the water layer present on the surface of a ferroelectric layer during the growth of ferroelectric domains in a single crystal of congruent LiTaO 3, by comparing results from atomic force microscopes operating in controlled atmosphere and in air. The overall kinetics of growth of domains is clearly slower under low relative humidity (RH), which suggests that the water layer present at the surface of the ferroelectric film plays an active role in the propagation of the domains. A finite element model is proposed in order to explain the differences, where the electric potential can propagate beyond the area of the tip in a conductive top layer adsorbed on the ferroelectric sample, this propagation being responsible for the switching of the polarization when the field is locally larger than the coercive field. According to this model, which describes fairly well the experimental observations, the growth of the domain can be described not only by a thermally activated process, but also using a purely electrical model, which strongly depends on the electrical properties of the layer covering the ferroelectric material.

Direct observations of radiation-enhanced transformations in glass

1983 ◽  
Vol 41 ◽  
pp. 354-355
Author(s):  
J. F. DeNatale ◽  
D. G. Howitt
Keyword(s):  
Glass Matrix ◽  
Diffusion Mechanism ◽  
Bubble Formation ◽  
Silicate Glasses ◽  
Phase Decomposition ◽  
Direct Observations ◽  
Thin Foils ◽  
Oxygen Bubble ◽  
Electron Energy Loss ◽  
Kinetics Of

The electron irradiation of silicate glasses containing metal cations produces various types of phase separation and decomposition which includes oxygen bubble formation at intermediate temperatures figure I. The kinetics of bubble formation are too rapid to be accounted for by oxygen diffusion but the behavior is consistent with a cation diffusion mechanism if the amount of oxygen in the bubble is not significantly different from that in the same volume of silicate glass. The formation of oxygen bubbles is often accompanied by precipitation of crystalline phases and/or amorphous phase decomposition in the regions between the bubbles and the detection of differences in oxygen concentration between the bubble and matrix by electron energy loss spectroscopy cannot be discerned (figure 2) even when the bubble occupies the majority of the foil depth.The oxygen bubbles are stable, even in the thin foils, months after irradiation and if van der Waals behavior of the interior gas is assumed an oxygen pressure of about 4000 atmospheres must be sustained for a 100 bubble if the surface tension with the glass matrix is to balance against it at intermediate temperatures.

Irradiation behavior of pyrolytic silicon carbide

1983 ◽  
Vol 41 ◽  
pp. 72-73
Author(s):  
R. J. Lauf
Keyword(s):  
Silicon Carbide ◽  
Fission Products ◽  
Thermodynamics And Kinetics ◽  
Neutron Fluences ◽  
Fuel Particles ◽  
Sic Coatings ◽  
Irradiation Behavior ◽  
Kinetics Of ◽  
Htgr Fuel

Fuel particles for the High-Temperature Gas-Cooled Reactor (HTGR) contain a layer of pyrolytic silicon carbide to act as a miniature pressure vessel and primary fission product barrier. Optimization of the SiC with respect to fuel performance involves four areas of study: (a) characterization of as-deposited SiC coatings; (b) thermodynamics and kinetics of chemical reactions between SiC and fission products; (c) irradiation behavior of SiC in the absence of fission products; and (d) combined effects of irradiation and fission products. This paper reports the behavior of SiC deposited on inert microspheres and irradiated to fast neutron fluences typical of HTGR fuel at end-of-life.

Electron-Mirror Microscopic Aspects of Ferroelectric Domains of BaTiO3 And Ca2Sr (C2H5CO2)6

1970 ◽  
Vol 28 ◽  
pp. 478-479
Author(s):  
Teruo Someya ◽  
Jinzo Kobayashi
Keyword(s):  
Surface Layer ◽  
Electric Fields ◽  
Quantitative Study ◽  
Recent Progress ◽  
Ferroelectric Domain ◽  
Resolving Power ◽  
Surface Pattern ◽  
Crystal Surfaces ◽  
One Dimensional ◽  
Ferroelectric Domains

Recent progress in the electron-mirror microscopy (EMM), e.g., an improvement of its resolving power together with an increase of the magnification makes it useful for investigating the ferroelectric domain physics. English has recently observed the domain texture in the surface layer of BaTiO3. The present authors ) have developed a theory by which one can evaluate small one-dimensional electric fields and/or topographic step heights in the crystal surfaces from their EMM pictures. This theory was applied to a quantitative study of the surface pattern of BaTiO3).

The Ordered Phase Formation in Ti-Al-Ga Alloys

1970 ◽  
Vol 28 ◽  
pp. 440-441
Author(s):  
Shiro Fujishiro ◽  
Harold L. Gegel
Keyword(s):  
Thermal Stability ◽  
High Temperature ◽  
Titanium Alloys ◽  
Growth Kinetics ◽  
Stoichiometric Composition ◽  
Good Potential ◽  
Alpha Titanium ◽  
Cold Rolled ◽  
Kinetics Of ◽  
Thermal Stability Of

Ordered-alpha titanium alloys having a DO19 type structure have good potential for high temperature (600°C) applications, due to the thermal stability of the ordered phase and the inherent resistance to recrystallization of these alloys. Five different Ti-Al-Ga alloys consisting of equal atomic percents of aluminum and gallium solute additions up to the stoichiometric composition, Ti3(Al, Ga), were used to study the growth kinetics of the ordered phase and the nature of its interface.The alloys were homogenized in the beta region in a vacuum of about 5×10-7 torr, furnace cooled; reheated in air to 50°C below the alpha transus for hot working. The alloys were subsequently acid cleaned, annealed in vacuo, and cold rolled to about. 050 inch prior to additional homogenization

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