Structures of sodium ammonium selenate dehydrate (ferroelectric phase) and lithium ammonium sulphate (antiferroelectric phase)

1978 ◽  
Vol 21 (1) ◽  
pp. 441-442 ◽  
Author(s):  
A. I. Kruglik ◽  
V. I. Zinenko ◽  
M. A. Simonov
Keyword(s):  
Ammonium Sulphate ◽  
Ferroelectric Phase ◽  
Antiferroelectric Phase

Effect of Glass Additive on Electrical Properties of PLZST Antiferroelectric Ceramics

2012 ◽  
Vol 512-515 ◽  
pp. 1300-1303 ◽  
Author(s):  
Gang Li ◽  
Tong Qing Yang ◽  
Jin Fei Wang ◽  
Zhao Jin Sun ◽  
Jian Qiang Guo
Keyword(s):  
Energy Storage ◽  
Remanent Polarization ◽  
Ferroelectric Phase ◽  
Breakdown Strength ◽  
Solid Phase ◽  
Pulsed Power ◽  
Solid Phase Reaction ◽  
Phase Reaction ◽  
Refined Grains ◽  
Antiferroelectric Phase

Alkali-free barium boroaluminosilicate glass-modified PLZST antiferroelectric ceramics with glass contents between 0 and 8 wt.% have been fabricated respectively by a traditional solid phase reaction. The PLZST ceramics doped with alkali-free barium boroaluminosilicate glass showed typical antiferroelectric phase when the glass contents were below 6 wt.% and the refined grains were observed. The addition of glass decreased the dielectric constant of samples. With increasing of the glass additives, both the Curie temperature and the remanent polarization deceased. It may be that Ba2+ entered in the perovskite structure, which acts as an important modified ion in the alkali-free barium boroaluminosilicate glass. Larger forward antiferroelectric-ferroelectric phase transition field (EAFE-FE >50 kV/cm) and higher breakdown strength (EBDS ≥105 kV/cm) were displayed in glass-modified PLZST ceramics. The improvement properties of samples were benefit for energy storage which is desired for the high power energy storage capacitors and pulsed power applications.

Etude quantitative de l'énergie libre de PbZrO3 pur et dopé avec Nb2O5

1969 ◽  
Vol 47 (22) ◽  
pp. 2439-2443 ◽  
Author(s):  
L. Benguigui ◽  
H. Hervet
Keyword(s):  
Free Energy ◽  
Ferroelectric Phase ◽  
Paraelectric Phase ◽  
Temperature Phase ◽  
Phase Determination ◽  
Electrical Field ◽  
Antiferroelectric Phase ◽  
Field Temperature ◽  
Heat Transition

Pure and Nb2O5 doped PbZrO3 exhibit the following phases: antiferroelectric, ferroelectric, and paraelectric. By means of measurements of heat transition, dielectric constant in paraelectric phase, determination of electrical field – temperature phase diagrams, we calculate the free energy of each phase. Given that the free energy can be developed in powers of the polarization, we show the coefficients of the ferroelectric phase are slightly modified by the addition of Nb2O5, while those of the antiferroelectric phase vary by a factor greater than two.

Domain structures in PbZr0.95 Ti0.05O3

1983 ◽  
Vol 41 ◽  
pp. 60-61
Author(s):  
K. Kuroda ◽  
A. H. Heuer
Keyword(s):  
Phase Transformations ◽  
Ferroelectric Phase ◽  
Ion Beam ◽  
Lead Zirconate ◽  
Microscopical Study ◽  
Thin Sections ◽  
Practical Applications ◽  
Antiferroelectric Phase ◽  
Diamond Saw ◽  
Electron Microscopical

Lead zirconate titenate (Pb(Zr,Ti)O3, PZT) is a well known piezoelectric substance. Three phases have been reported in modified PbZr0.95Ti0.05O3 (PZT 95/5) bodies -- a low temperature rhombohedral ferroelectric phase (FR1), a high temperature rhombohedral ferroelectric phase (FR2) and a cubic paraelectric phase (PC). A pressure induced ferroelectric to antiferroelectric phase transformation has also been reported in modified PZT 95/5 ceramics. These phase transformations are of technological importance, as this ceramic has practical applications as a power source in which large quantities of charge are released by shock wave depolarization.Both as-fired and pressure de-poled samples of PZT 95/5 ceramics with 0.8% Nb were investigated by transmission electron microscopy. Specimens for electron microscopical study were prepared from thin sections, which had been sliced by diamond saw and then mechanically polished with 600 grit SiC paper followed by diamond polishing to about 100 μm thickness. These specimens were then argon ion milled to electron transparency; a liquid N2 cooled stage was used to try and prevent the occurrence of phase transformations due to heating during ion beam thinning. Special care was also taken to minimize beam heating during electron microscopical observation.

Effect of substituents with different valences on antiferroelectric stability of antiferroelectric lead zirconate ceramics

1999 ◽  
Vol 14 (11) ◽  
pp. 4251-4258 ◽  
Author(s):  
Qi Tan ◽  
Z. Xu ◽  
Dwight Viehland
Keyword(s):  
Electron Diffraction ◽  
Phase Stability ◽  
Dielectric Spectroscopy ◽  
Ferroelectric Phase ◽  
Lead Zirconate ◽  
Phase Region ◽  
Effect Of Substituents ◽  
Antiferroelectric Phase ◽  
Ionic Size ◽  
The Stability

The effect of lower valent substituents on the stability of the antiferroelectric phase of lead zirconate was studied by dielectric spectroscopy, Sawyer–Tower polarization methods, and electron diffraction techniques. The stability of an intermediate ferroelectric phase region was found to be enhanced with increasing lower valent substitution concentration. The influences of substituents of different ionic size and valence on the stabilization of the intermediate ferroelectric phase were differentiated. In general, lower valent substituents, such as K+ and Fe3+ affected antiferroelectric phase stability more significantly than higher valent ones.

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