scholarly journals A-site magnetism in A-site-ordered perovskite-structure oxides

2011 ◽  
Vol 249 (3) ◽  
pp. 423-434 ◽  
Author(s):  
Yuichi Shimakawa ◽  
Takashi Saito
Keyword(s):  
Perovskite Structure ◽  
A Site

A-site cation off-centering contribution on ferroelectricity and piezoelectricity in pseudo-cubic perovskite structure of Bi-based lead-free piezoelectrics

2021 ◽  
Vol 205 ◽  
pp. 114176
Author(s):  
Sangwook Kim ◽  
Hyunwook Nam ◽  
Ichiro Fujii ◽  
Shintaro Ueno ◽  
Chikako Moriyoshi ◽  
...  
Keyword(s):  
Perovskite Structure ◽  
Lead Free ◽  
A Site

The rich physics of A-site-ordered quadruple perovskite manganites AMn7O12

2021 ◽  
Author(s):  
Alexei A. Belik ◽  
Roger D Johnson ◽  
Dmitry Khalyavin
Keyword(s):  
Perovskite Structure ◽  
Double Exchange ◽  
Perovskite Manganites ◽  
Phonon Coupling ◽  
Electron Phonon Coupling ◽  
Jahn Teller ◽  
The Rich ◽  
A Site ◽  
Small Polarons

Perovskite-structure AMnO3 manganites played an important role in the development of numerous physical concepts such as double exchange, small polarons, electron-phonon coupling, and Jahn−Teller effects, and they host a variety...

Pressure Effect on Intersite Charge Transfer in A-site-Ordered Double-Perovskite-Structure Oxide

2012 ◽  
Vol 24 (11) ◽  
pp. 2235-2239 ◽  
Author(s):  
You-wen Long ◽  
Takateru Kawakami ◽  
Wei-tin Chen ◽  
Takashi Saito ◽  
Tetsu Watanuki ◽  
...  
Keyword(s):  
Charge Transfer ◽  
Perovskite Structure ◽  
Pressure Effect ◽  
Double Perovskite ◽  
A Site

scholarly journals Inorganic Co-Crystal Formation and Thermal Disproportionation in a Dicyanometallate 'Superperovskite'

2019 ◽  
Author(s):  
Joshua A. Hill ◽  
Claire A. Murray ◽  
Chiu C. Tang ◽  
Peter M. M. Thygesen ◽  
Amber L. Thompson ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Phase Transformation ◽  
Perovskite Structure ◽  
Structure Type ◽  
Crystal Formation ◽  
Thermally Driven ◽  
New Type ◽  
A Site ◽  
Inorganic Components

<div> <div> <div> <p>We report the synthesis, crystal structure, and thermally- driven phase transformation of the dicyanometallate super- perovskite co-crystal [NBu4]Mn[Au(CN)2]3·[NBu4]ClO4. This phase is understandable in terms of the conventional ABX3 perovskite structure type, but with the NBu+4 A-site cation displaced onto the perovskite cage face and 1-dimensional AX′ chains included within framework pores opened up by these displacements. On heating to 380K, the co-crystal disproportionates into its two inorganic components: a bcs-structured ABX3 phase and [NBu4 ]ClO4 . This system illustrates a new type of structural and phase complexity accessible to dicyanometallate perovskites. </p> </div> </div> </div>

scholarly journals Dielectric and Impedance Studies of (Ba,Ca)TiO3 Ceramics Obtained from Mechanically Synthesized Powders

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4036
Author(s):  
Kamil Feliksik ◽  
Lucjan Kozielski ◽  
Izabela Szafraniak-Wiza ◽  
Tomasz Goryczka ◽  
Małgorzata Adamczyk-Habrajska
Keyword(s):  
Mechanochemical Synthesis ◽  
Calcium Ion ◽  
Perovskite Structure ◽  
Calcium Concentration ◽  
Perovskite Phase ◽  
Economic Benefits ◽  
Ambient Conditions ◽  
Ceramic Samples ◽  
A Site ◽  
Stoichiometry Control

Mechanochemical synthesis offers unique possibility of perovskite phase formation at ambient conditions that is very attractive (simplifies production, allows strict stoichiometry control and brings economic benefits). In this work the mechanochemical synthesis has been used for preparation ofBa1−xCaxTiO3 (0.2 ≤ x ≤ 0.3) powders from simple oxides. The 20 h milled powders have been uniaxially pressed and sintered in order to get the ceramic samples. The sample morphologies have been observed by scanning electron microscopy. Dielectric and impedance studies have been performed on ceramics. The obtained results indicate that the two mechanism of doping occurred. The first one is observed for the lower calcium concentration (below 0.3) and consists of the introduction of calcium ion into the A site of the perovskite structure. The second one is observed for the higher calcium concentration (equal 0.3). In this case the calcium ions partially occupies the B site in the perovskite structure. Both cases have different influence on the final properties of the ceramics because they induce different defects.

Chemical Composition, Geochemical Alteration, and Radiation Damage Effects in Natural Perovskite

1997 ◽  
Vol 506 ◽  
Author(s):  
Gregory R. Lumpkin ◽  
Michael Colella ◽  
Katherine L. Smith ◽  
Roger H. Mitchell ◽  
Alf Olav Larsen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Composition ◽  
Electron Diffraction ◽  
Perovskite Structure ◽  
Alpha Decay ◽  
Primary Result ◽  
Transmission Electron ◽  
A Site ◽  
Dose Levels

ABSTRACTPreliminary analytical and transmission electron microscopy (AEM and TEM) results for a small suite of natural perovskites are reported in this paper and discussed in relation to previous work. We show that perovskite compositions in Synroc and tailored ceramics plot within the known fields of natural perovskite compositions. AEM analyses and electron diffraction work on selected samples indicate that they are predominantly stoichiometric variants of the cubic perovskite structure. Geochemical alteration was observed in one sample of loparite from Bratthagen, Norway. The primary result of this alteration was leaching of Na from the A-site. Although sufficient alpha-decay dose levels for complete amorphization are not realized in this suite of samples, the available data bracket the beginning of the crystalline-amorphous transformation at doses that are ∼ 2-4 times greater than those of zirconolite of similar age. These results may be due to fundamental differences in the damage annealing rates of perovskite and zirconolite.

Piezoelectric Properties and Dielectric Property of Li Added KNN Ceramics

2013 ◽  
Vol 566 ◽  
pp. 72-75 ◽  
Author(s):  
Akihiro Mitani ◽  
Yoshinari Oba
Keyword(s):  
Dielectric Property ◽  
Curie Temperature ◽  
Perovskite Structure ◽  
High Performance ◽  
Piezoelectric Properties ◽  
Piezoelectric Materials ◽  
Environmental Issues ◽  
Lead Free ◽  
High Curie Temperature ◽  
A Site

Recently, high performance lead-free piezoelectric materials are strongly demanded for environmental issues. (K0.5Na0.5)NbO3 (KNN) has been attracting interest as lead-free piezoelectric ceramics because of its high Curie temperature and excellent piezoelectric properties. In this study, we investigated effects of Li addition on piezoelectric properties of (Li,Na,K)(Nb+Ta)O3+CuO,BaTiO3 . We found that optimum Li ratio of A site and B site on the perovskite structure increases relative density and .

Influences of A-site Partial Substitution for BaCo0.7Fe0.3O3Oxide on Perovskite Structure and Oxygen Permeability

2002 ◽  
Vol 31 (3) ◽  
pp. 344-345 ◽  
Author(s):  
Kazuya Kinoshita ◽  
Hajime Kusaba ◽  
Go Sakai ◽  
Kengo Shimanoe ◽  
Norio Miura ◽  
...  
Keyword(s):  
Perovskite Structure ◽  
Oxygen Permeability ◽  
Partial Substitution ◽  
A Site

Microwave Dielectric Properties of Ca[(Li1/3Nb2/3)0.95Zr0.15]O3+δ Ceramics with Ba2+ Substitution at A-Site

2007 ◽  
Vol 336-338 ◽  
pp. 196-198
Author(s):  
Dong Xiang Zhou ◽  
G. Xiong ◽  
Shu Ping Gong ◽  
Jun Zhao ◽  
M.Z. Hu ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Perovskite Structure ◽  
Single Phase ◽  
Microwave Dielectric Properties ◽  
Bond Valence ◽  
Microwave Properties ◽  
Microwave Dielectric ◽  
Orthorhombic Perovskite ◽  
A Site

The microwave properties of (Ca1-xBax)[(Li1/3Nb2/3)0.95Zr0.15]O3+δ(0.0≤x≤0.2, CBLNZ) ceramics were investigated. A single phase with orthorhombic perovskite structure was obtained at x = 0.0 − 0.025. Both the εr and Qf value firstly increased with increasing Ba2+ content, and then began to decrease at x = 0.025. The τf value increased from −9.4 ppm/°C at x=0.0 to 18ppm/°C at x=0.2, which could be explained by the decrease of B-site bond valence in perovskite structure.

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