Stabilization of the perovskite phase and dielectric properties in the Pb(Mg1/3Nb2/3)O3?BaTiO3 system

1991 ◽  
Vol 26 (1) ◽  
pp. 56-60 ◽  
Author(s):  
Dong Heon Kang ◽  
Kl Hyun Yoon
Keyword(s):  
Dielectric Properties ◽  
Perovskite Phase

Influence of Excess Bi2O3 and Na2Co3 on Crystal Structure and Microstructure of Bismuth Sodium Titanate Ceramics

2011 ◽  
Vol 474-476 ◽  
pp. 1711-1714 ◽  
Author(s):  
Panadda Sittiketkron ◽  
Arrak Klinbumrung ◽  
Theerachai Bongkarn
Keyword(s):  
Crystal Structure ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Average Particle Size ◽  
Sodium Titanate ◽  
Solid State Reaction Method ◽  
Lattice Parameter ◽  
Rhombohedral Structure ◽  
Average Particle ◽  
Average Grain Size

This study investigated the influence of excess Bi2O3 and Na2CO3 on the crystal structure, microstructure and dielectric properties of (Bi0.5Na0.5)TiO3 (BNT) ceramics. The BNT ceramics were synthesized using the solid-state reaction method with various excess Bi2O3 and Na2CO3 levels (0, 1, 2, 3 and 4 mol%). The X-ray characterization revealed that all samples had a rhombohedral structure. A pure perovskite phase was obtained in all samples. The lattice parameter a tended to increase with increased excess Bi2O3 and Na2CO3 content in the calcined powders and sintered ceramics. The average particle size increased while, the average grain size tended to decreased with increased of excess Bi2O3 and Na2CO3 content. The depolarization temperature (Td) and the Curie temperature (Tc) were slightly decreased with the increase of excess Bi2O3 and Na2CO3 content. The dielectric properties were related to the density.

Structure and Dielectric Properties of Zn Doped PST Thin Films Prepared by Sol-Gel Method

2007 ◽  
Vol 336-338 ◽  
pp. 283-286 ◽  
Author(s):  
Zan Zheng ◽  
Xiao Ting Li ◽  
Gao Rong Han ◽  
Wen Jian Weng ◽  
Pi Yi Du
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Phase Structure ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Dip Coating ◽  
In Doping ◽  
Ito Glass ◽  
Coating Method ◽  
Dip Coating Method

(PbySr1-y)ZnxTi1-xO3-x thin films were prepared on ITO/glass substrate by sol–gel process using dip-coating method. The phase structure, morphology, and dielectric properties of thin films were investigated by XRD, SEM and impedance analyzer, respectively. The perovskite phase structure was exhibited in the Zn-doped PST thin films. The formation ability of the thin films of the perovskite phase and its grain size decreased with the increase in doping Zn. The dielectric constant of the thin film was influenced by oxygen vacancies which could be controlled by Zn doping.

Dielectric Properties of Mn, Co, and Ni-Doped LaSrFeO3 Films with Different Annealing Atmosphere

2015 ◽  
Vol 740 ◽  
pp. 28-31
Author(s):  
Yang Lu Hou ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Hong Di Xue
Keyword(s):  
Thin Films ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Film Surface ◽  
Annealing Atmosphere ◽  
Single Perovskite Phase ◽  
Gel Technique

Mn, Co, and Ni-doped La0.5Sr0.5FeO3 thin films were prepared by the sol-gel technique with different annesling atmosphere. The structure and dielectric properties of the films were researched by XRD, SEM and Agilent. The study found that LSF-Mn (Co, Ni) films under the argon annealing atmosphere were have optimal dielectric properties. And Mn, Co, Ni elements are integrated into La0.5Sr0.5FeO3 lattices with the single perovskite phase. And uniform grain was distribution on the film surface.

Effect of Sr/Ba Ratio on Dielectric Properties of BSTN Ceramics

2007 ◽  
Vol 336-338 ◽  
pp. 125-128 ◽  
Author(s):  
Zong Hui Zhou ◽  
Xin Cheng ◽  
Pi Yi Du ◽  
Jun Chang ◽  
Shi Feng Huang ◽  
...  
Keyword(s):  
Dielectric Constant ◽  
Phase Composition ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Tungsten Bronze ◽  
Dielectric Constants ◽  
Composite Ceramics ◽  
Impedance Analyzer ◽  
Applied Frequency ◽  
Two Phases

The phase composition of (1-x)BaO·xSrO·0.7TiO2·0.3Nb2O5 (BSTN) composite ceramics was analyzed by XRD, and the effect of Sr/Ba ratio on the dielectric properties of BSTN was investigated by impedance analyzer. The results showed that any sample with different x value contained two phases-the perovskite phase and the tungsten bronze phase. The dielectric constants of BSTN basically decreased while the tanδ increased with the increase in x value. Both dielectric constant and tanδ decreased with the applied frequency increased for the same x value. There were two Curie points for BSTN composite ceramics. The first one belonging to the perovskite phase decreased with the increase in x value, but the second one belonging to the tungsten bronze phase kept almost constant at about 300°C.

scholarly journals Особенности структуры и свойств тонких пленок цирконата-титаната свинца с сильно неоднородным распределением состава по толщине

2019 ◽  
Vol 45 (16) ◽  
pp. 41
Author(s):  
Д.М. Долгинцев ◽  
М.В. Старицын ◽  
В.П. Пронин ◽  
Е.Ю. Каптелов ◽  
С.В. Сенкевич ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Comparative Study ◽  
Radio Frequency ◽  
Lead Zirconate Titanate ◽  
Phase State ◽  
Perovskite Phase ◽  
Lead Zirconate ◽  
Gas Pressure ◽  
Magnetron Deposition ◽  
State Composition

Two-layer thin lead zirconate titanate films in which the lead content differed by 20% were formed by radio-frequency magnetron deposition under variation of the working gas pressure. A comparative study of the phase state, composition, and dielectric properties of bilayer structures differing in the sequence of layers deposition has been carried out. It is shown that, depending on the order of the layers, the conditions of crystallization of the perovskite phase and the unipolar properties of the films change significantly.

scholarly journals Influence of Microstructure-Evolution Changes on the Dielectric Properties of Strontium Titanate Prepared via Mechanical Alloying

2019 ◽  
Vol 7 (2) ◽  
Author(s):  
Mutia Suhaibah Abdullah ◽  
Dayang Nur Fazliana Abdul Halim ◽  
Jumiah Hassan ◽  
Mansor Hashim ◽  
Alex See ◽  
...  
Keyword(s):  
Grain Size ◽  
Dielectric Properties ◽  
Mechanical Alloying ◽  
Dielectric Material ◽  
Perovskite Phase ◽  
Morphological Changes ◽  
Milled Powder ◽  
Sudden Increase ◽  
Common Trend ◽  
Lower Frequency Region

SrTiO3 is a dielectric material of considerable interest. However, the relationships between microstructure and dielectric properties have not been studied in detail. Hence, we have undertaken an extensive experimental work to study the evolution of the dielectric properties against morphological changes of SrTiO3. SrTiO3 was prepared using the mechanical alloying method and samples with nano-sized starting powder were obtained. The milled powder was pressed into pellets and sintered at various temperatures ranging from 500 °C to 1400 °C. XRD studies showed that these ceramics completely formed a perovskite phase at 900 °C. FeSEM studies show the presence of small grain sizes ranging from 120 to 600 nm. Dielectric constant (εr’) and dielectric loss tangent (tan δ) were measured as a function of frequency and correlated with the microstructure. εr’ and tan δ against frequency show a falling trend at the lower frequency region due to the changing interfacial effect. For sintering temperatures 1000 °C to 1100 °C, grain size and XRD peak data show a significant increase with the corresponding increase in εr’, suggesting a sudden increase in the polarizability due to significant increase in crystallinity. With increasing sintering temperature, εr’ increased proportionally with XRD peak and grain size increases, further confirming polarizability and crystallinity relationship. tan δ correlation with microstructure does not have a common trend.

Structure and Dielectric Properties of Mg, Cr-Doped LaSrFeO3 Films

2014 ◽  
Vol 538 ◽  
pp. 11-14
Author(s):  
Yang Lu Hou ◽  
Xing Hua Fu ◽  
Wen Hong Tao ◽  
Xin Jin
Keyword(s):  
Thin Film ◽  
Thin Films ◽  
Grain Size ◽  
Dielectric Properties ◽  
Perovskite Phase ◽  
Sol Gel ◽  
Doping Amount ◽  
Single Perovskite Phase ◽  
Pure Perovskite Phase ◽  
Mg Doped

Mg-doped LaFeO3 thin film and Mg, Cr-doped La0.5Sr0.5FeO3 thin films were prepared by the sol-gel method. The change rules of structure and dielectric properties of the films were studied by XRD, SEM, and Agilent. The dielectric properties of La0.5Sr0.5FeO3 and LaFeO3 films were improved by the substitute with Mg and Cr. The doping amount of Mg and Cr for the optimal dielectric properties of La0.5Sr0.5FeO3 films is 45mol%, 25mol%, respectively, and for LaFeO3, the doping amount of Mg is 8mol%. The observed pure perovskite phase of the doped films suggested the dissolution of Mn, Co, and Ni in La0.5Sr0.5FeO3 crystal lattice. Mg and Cr were integrate in the lattice of LaFeO3 and La0.5Sr0.5FeO3, and mineral is single perovskite phase. The surface of the film is smooth, without cracks, surface grain size distribution and had uniform grain size.

Effect of B2O3 Flux on the Crystal Structure, Dielectric Properties of (K 0.5Na0.5)NbO3 Single Crystal Grown by Flux Method

2012 ◽  
Vol 584 ◽  
pp. 150-154
Author(s):  
Rajemepu Saravanan ◽  
Dodla Rajesh ◽  
S. Velu Rajasekaran ◽  
Rajakempu Perumal ◽  
M. Chitra ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
Single Crystals ◽  
Solution Method ◽  
Perovskite Phase ◽  
Eutectic Mixture ◽  
Sodium Potassium ◽  
Sodium Potassium Niobate ◽  
Morphological Studies ◽  
Temperature Solution ◽  
Tetragonal Phase Transition

Lead free piezoelectric single crystals of sodium potassium niobate (K 0.5Na0.5)NbO3 single crystals were grown by high-temperature solution method using B2O3 flux The KNN crystals grown by without B2O3 flux and with B2O3 flux are referred to as samples A and B respectively. It was found that additions of small amounts of boron oxide B2O3 further lower the melting temperature of the eutectic mixture and exhibits excellent dielectric properties. Phase analysis showed that all samples crystallized in pure orthorhombic perovskite phase. AFM morphological studies show that the root mean square (rms) roughness values were measured to be, 5.3nm and 6.96nm for the sample A and sample B crystal respectively. A slight decrease in the orthorhombic to tetragonal phase transition temperature TOT> and Curie temperature Tc has been observed in sample B when compared with sample A.

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