Destabilization of ferroelectric order in bismuth perovskite ceramics by A-site vacancies

2012 ◽  
Vol 70 ◽  
pp. 98-100 ◽  
Author(s):  
Hyoung-Su Han ◽  
Chang-Won Ahn ◽  
Ill Won Kim ◽  
Ali Hussain ◽  
Jae-Shin Lee
Keyword(s):  
Perovskite Ceramics ◽  
Bismuth Perovskite ◽  
A Site ◽  
Ferroelectric Order

Lead-free electrostrictive bismuth perovskite ceramics with thermally stable field-induced strains

2011 ◽  
Vol 65 (17-18) ◽  
pp. 2607-2609 ◽  
Author(s):  
Vu Diem Ngoc Tran ◽  
Hyoung-Su Han ◽  
Chang-Ho Yoon ◽  
Jae-Shin Lee ◽  
Wook Jo ◽  
...  
Keyword(s):  
Lead Free ◽  
Thermally Stable ◽  
Perovskite Ceramics ◽  
Bismuth Perovskite ◽  
Stable Field

scholarly journals Single- or double A-site cations in A3Bi2I9 bismuth perovskites: What is the suitable choice?

2021 ◽  
Author(s):  
Feray Ünlü ◽  
Ashish Kulkarni ◽  
Khan Lê ◽  
Christoph Bohr ◽  
Andrea Bliesener ◽  
...  
Keyword(s):  
Power Conversion Efficiency ◽  
Conversion Efficiency ◽  
Power Conversion ◽  
Photovoltaic Performance ◽  
Organic Cations ◽  
Device Performance ◽  
Inorganic Cations ◽  
Device Efficiency ◽  
Bismuth Perovskite ◽  
A Site

Abstract Investigations on the effect of single or double A-site cation engineering on the photovoltaic performance of bismuth perovskite-inspired materials (A3Bi2I9) are rare. Herein, we report novel single- and double-cation based bismuth perovskite-inspired materials developed by (1) completely replacing CH3NH3+ (methylammonium, MA+) in MA3Bi2I9 with various organic cations such as CH(NH2)2+ (formamidinium, FA+), (CH3)2NH2+ (dimethylammonium, DMA+), C(NH2)3+ (guanidinium, GA+) and inorganic cations such as cesium (Cs+), rubidium (Rb+), potassium (K+), sodium (Na+) and lithium (Li+) and (2) partially replacing MA+ with Cs+ in different stoichiometric ratios. Compared to single-cation based bismuth perovskite devices, the double-cation bismuth perovskite device showed an increment in the device power conversion efficiency (PCE) up to 1.5% crediting to the reduction in the bandgap. This is the first study demonstrating double-cation based bismuth perovskite showing bandgap reduction and increment in device efficiency and opens up the possibilities towards compositional engineering for improved device performance. Graphic Abstract

Significantly enhanced energy storage density and efficiency of BNT-based perovskite ceramics via A-site defect engineering

2020 ◽  
Vol 30 ◽  
pp. 392-400 ◽  
Author(s):  
Fei Yan ◽  
Kaiwei Huang ◽  
Tao Jiang ◽  
Xiaofeng Zhou ◽  
Yunjing Shi ◽  
...  
Keyword(s):  
Energy Storage ◽  
Energy Storage Density ◽  
Defect Engineering ◽  
Storage Density ◽  
Perovskite Ceramics ◽  
A Site

scholarly journals Synthesis and in situ ion irradiation of A-site deficient zirconate perovskite ceramics

2020 ◽  
Vol 8 (37) ◽  
pp. 19454-19466
Author(s):  
Sebastian M. Lawson ◽  
Graeme Greaves ◽  
Lewis R. Blackburn ◽  
Rachel Chapman ◽  
Neil C. Hyatt ◽  
...  
Keyword(s):  
Ion Irradiation ◽  
Varied Temperature ◽  
Perovskite Ceramics ◽  
A Site

The influence of A-site vacancies on zirconate perovskite structured ceramics of formula A1−xLa2x/3ZrO3 (A = Ca, Sr, Ba) has been investigated using 400 keV Kr+in situ ion irradiation in a TEM with varied temperature from 100 K to 673 K.

scholarly journals Phase, microstructure and microwave dielectric properties of A-site deficient (La, Nd)2/3TiO3 perovskite ceramics

2015 ◽  
Vol 33 (1) ◽  
pp. 126-130 ◽  
Author(s):  
Muhammad Saleem ◽  
Yaseen Iqbal ◽  
Shan Qin ◽  
Xiang Wu ◽  
Feng Zhu
Keyword(s):  
Dielectric Properties ◽  
Sintering Temperature ◽  
Microwave Dielectric Properties ◽  
Secondary Phase ◽  
Network Analyzer ◽  
Air Atmosphere ◽  
Microwave Dielectric ◽  
Perovskite Ceramics ◽  
Xrd Patterns ◽  
A Site

Abstract(La, Nd)2/3TiO3 ceramics were prepared through a conventional solid state mixed oxide route. For phase and microstructure analysis, XRD and SEM were used, respectively. Microwave dielectric properties were measured using a network analyzer. XRD patterns revealed the formation of the parent (La, Nd)2/3TiO3 phase along with (La, Nd)4Ti9O24 as a secondary phase. The microstructure consisted of rectangular and needle shaped grains, which decreased in size from 4 μm to 2 μm with an increase in sintering temperature from 1300 °C to 1350 °C. Decrease in grain size caused an increase in density of the samples from 4.81 g/cm3 to 5.17 g/cm3. Microwave dielectric properties of the samples calcined and sintered in air atmosphere were εr = 40.35, Q × f = 3499 GHz and τf = 0 ppm/°C, whereas for a sample calcined in nitrogen and sintered in air they were εr = 40.18, Q × f = 4077 GHz and τf = +4.9 ppm/°C, respectively.

EFFECT OF SUBSTITUTION OF K FOR Na ON THE FERROELECTRIC STABILITY AND PROPERTIES OF (Bi1/2Na1/2)TiO3-BaTiO3-(K0.5Na0.5)NbO3

2010 ◽  
Vol 03 (01) ◽  
pp. 41-44 ◽  
Author(s):  
WOOK JO ◽  
JÜRGEN RÖDEL ◽  
JONG-SOOK LEE ◽  
YOON-HEE BAIK ◽  
CHAN PARK
Keyword(s):  
Phase Transition ◽  
Hysteresis Loops ◽  
Structural Difference ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
The Stability ◽  
A Site ◽  
Permittivity Measurements ◽  
Electric Field Induced Strain ◽  
Ferroelectric Order

The effect of an isovalent chemical variation in A site cations on the stability of ferroelectric order and consequent changes in the electrical properties of ferroelectric 0.93( Bi 1/2 Na 1/2) TiO 3-0.05 BaTiO 3-0.02( K 0.5 Na 0.5) NbO 3 (0.93 BNT -0.05 BT -0.02 KNN ) lead-free piezoceramic at the morphotropic phase boundary (MPB) was investigated by substituting K for Na . X-ray diffraction analysis reveals that all the studied compositions undergo an irreversible phase transition from a pseudocubic to a mixture of rhombohedral and tetragonal phases during poling. In spite of the absence of an obvious structural difference, both electric-field-induced strain and polarization hysteresis loops show a clear distinction. It was found that the effect of substitution is so drastic that about 0.5 at% substitution renders the material softer and more than 1.0 at% results in a significant destabilization of the ferroelectric order. However, no notable difference in the temperature dependent permittivity measurements was detected, which suggests that the depoling of these materials has some other origin than a symmetry-breaking phase transition.

Influence of A-site doping on properties of lead-free KNN-based perovskite ceramics

2021 ◽  
Vol 575 (1) ◽  
pp. 158-166
Author(s):  
E. D. Politova ◽  
G. M. Kaleva ◽  
A. V. Mosunov ◽  
S. Yu. Stefanovich ◽  
N. V. Sadovskaya ◽  
...  
Keyword(s):  
Lead Free ◽  
Perovskite Ceramics ◽  
A Site

Eels Under Standing Wave Conditions

1982 ◽  
Vol 40 ◽  
pp. 492-495
Author(s):  
O.L. Krivanek ◽  
J. TaftØ
Keyword(s):  
Standing Wave ◽  
Wave Conditions ◽  
Set Up ◽  
A Site ◽  
Complex Crystal

It is well known that a standing electron wavefield can be set up in a crystal such that its intensity peaks at the atomic sites or between the sites or in the case of more complex crystal, at one or another type of a site. The effect is usually referred to as channelling but this term is not entirely appropriate; by analogy with the more established particle channelling, electrons would have to be described as channelling either through the channels or through the channel walls, depending on the diffraction conditions.

Head Size and DNA Content in Bacteriophage T4

1972 ◽  
Vol 30 ◽  
pp. 200-201
Author(s):  
Fred Eiserling ◽  
A. H. Doermann ◽  
Linde Boehner
Keyword(s):  
Electron Microscopy ◽  
Dna Content ◽  
Bacteriophage T4 ◽  
Head Size ◽  
Virus Particles ◽  
Altered Protein ◽  
A Cell ◽  
Bacterial Viruses ◽  
A Site ◽  
Protein Shell

The control of form or shape inheritance can be approached by studying the morphogenesis of bacterial viruses. Shape variants of bacteriophage T4 with altered protein shell (capsid) size and nucleic acid (DNA) content have been found by electron microscopy, and a mutant (E920g in gene 66) controlling head size has been described. This mutant produces short-headed particles which contain 2/3 the normal DNA content and which are non-viable when only one particle infects a cell (Fig. 1).We report here the isolation of a new mutant (191c) which also appears to be in gene 66 but at a site distinct from E920g. The most striking phenotype of the mutant is the production of about 10% of the phage yield as “giant” virus particles, from 3 to 8 times longer than normal phage (Fig. 2).

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