Ionic Conductivity Measurements of LaF3 Polycrystalline Powders

2010 ◽  
Vol 663-665 ◽  
pp. 678-681
Author(s):  
Ming Zhou ◽  
Yan Wen Tian
Keyword(s):  
Ionic Conductivity ◽  
Impedance Spectroscopy ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Microwave Method ◽  
Conductivity Measurements ◽  
Industrial Grade ◽  
Gel Technique ◽  
Polycrystalline Powder

With the help of impedance spectroscopy, the complex impedances of three kinds of ultrafine LaF3 polycrystalline powders (industrial grade LaF3 polycrystalline powder, ultrafine LaF3 polycrystalline powder prepared with sol-gel technique, and ultrafine LaF3 polycrystalline powder prepared with microwave method) were measured, and their ionic conductivities were derived. It is found that the ionic conductivities of the industrial grade LaF3 polycrystalline powder and the ultrafine LaF3 polycrystalline powder prepared with microwave method are higher than that of the ultrafine LaF3 polycrystalline powder prepared with sol-gel technique.

Ionic Conduction Performance of Solid Electrolyte Materials

2010 ◽  
Vol 156-157 ◽  
pp. 799-802
Author(s):  
Ming Zhou ◽  
Yan Wen Tian
Keyword(s):  
Experimental Data ◽  
Ionic Conductivity ◽  
Solid Electrolyte ◽  
Ionic Conduction ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Microwave Method ◽  
Ionic Conductors ◽  
Base Materials ◽  
Polycrystalline Powder

This experiment composes irreversible cells using ultrafine electrolyte materials and platinum slices, to measure the ionic conductivity the cells at normal temperatures with the help of impedance 1286 spectroscopy. We have calculated the ionic conductivities, which indicate that the ionic conductivities of the merchant LaF3 polycrystalline powder and the powder by microwave method are higher than the ones of LaF3 crystal and the powder by Sol-Gel method, to achieve 10-6 Scm-1, so, they are better ionic conductors at normal temperature and can be used as sensor base materials. The experimental data show that O- participates in ionic conduction.

Characterization of New Ionically Conducting Peo-Based Networks by Diffusion, Elasticity Modulus and Ionic Conductivity Measurements

1992 ◽  
Vol 293 ◽  
Author(s):  
Herve Cheradame ◽  
F. Desbat ◽  
P. Mercier-Niddam ◽  
S. Boileau
Keyword(s):  
Diffusion Coefficient ◽  
Ionic Conductivity ◽  
Elasticity Modulus ◽  
Sol Gel ◽  
Cation Transport ◽  
Lithium Cation ◽  
Conductivity Measurements ◽  
Conducting Materials ◽  
Diffusion Studies

AbstractIonically conducting materials containing PEO were prepared from telechelic di(methyl-diethoxy-silane) PEO, synthesized by the hydrosilylation of telechelic diallyl-PEO with methyldiethoxysilane. The network is obtained by the usual sol-gel chemistry. Then, it is filled with LiClO4 by diffusion of the salt and further drying. A comparison is made with the same kind of materials crosslinked using urethane chemistry. Diffusion studies show that the diffusion coefficient of solvent is similar for both types of materials, whilst the ionic conductivity is higher for the networks crosslinked with siloxane bonds. An experiment of diffusion of LiClO4 without solvent showed that this salt has a diffusion coefficient of the order of 2.10-8 cm2.sec-1 at 34°C. The conductivity calculated from this determination is compatible with the mechanism of lithium cation transport by the diffusion of salt molecules. Elasticity modulus measurements show that the salt aggregates are essentially located within the crosslinks at low concentration, but also in the PEO chains for salt concentrations higher than 1 mol/l.

Ionic conductivity in nanocrystalline Gd doped ceria

2008 ◽  
Vol 1122 ◽  
Author(s):  
Gianguido Baldinozzi ◽  
David Simeone ◽  
Dominique Gosset ◽  
Mickael Dollé ◽  
Georgette Petot-Ervas
Keyword(s):  
Grain Size ◽  
Ionic Conductivity ◽  
Sol Gel ◽  
Doped Ceria ◽  
Narrow Size Distribution ◽  
Conductivity Measurements ◽  
X Ray Diffraction ◽  
X Ray ◽  
Grain Sizes ◽  
The Impact

AbstractWe have synthesized Gd-doped ceria polycrystalline samples (5, 10, 15 %mol), having relative densities exceeding 95% and grain sizes between 30 and 160 nm after axial hot pressing (750 °C, 250 MPa). The samples were prepared by sintering nanopowders obtained by sol-gel chemistry methods having a very narrow size distribution centered at about 16 nm. SEM and X-ray diffraction were performed to characterize the sample microstructures and to assess their structures. We report ionic conductivity measurements using impedance spectroscopy. It is important to investigate the properties of these systems with sub-micrometric grains and as a function of their composition. Therefore, samples having micrometric and nanometric grain sizes (and different Gd content) were studied. Evidence of Gd segregation near the grain boundaries is given and the impact on the ionic conductivity, as a function of the grain size and Gd composition, is discussed and compared to microcrystalline samples.

scholarly journals [MG49-LiClO4]:[TiO2-SiO2] Polymer Electrolytes: In Situ Preparation and Characterization

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
Oon Lee Kang ◽  
Azizan Ahmad ◽  
Nur Hasyareeda Hassan ◽  
Usman Ali Rana
Keyword(s):  
Polymer Electrolytes ◽  
Structural Changes ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
In Situ Techniques ◽  
In Situ Preparation ◽  
Solution Cast ◽  
Gel Technique ◽  
Cast Technique

In the present research, [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes were first prepared through simple stepwise in situ techniques: sol-gel technique and solution-cast technique. [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes were then characterized through different experimental techniques. [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes had exhibited significant structural changes upon different salt concentrations. In the present investigation, [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes had attained maximum ionic conductivities (σ~10-7 S/cm at ambient temperature; 10−4 S/cm at 100°C) upon 25 wt.% salt insertion. [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes had exhibited distinct conduction mechanisms in similar experimental configuration. [MG49-LiClO4]:[HNO3-THF/TiO2-SiO2] and [MG49-LiClO4]:[ClHNO2-THF/TiO2-SiO2] polymer electrolytes had exhibited different stability characteristics over certain operational condition.

On the Sol-Gel Synthesis and Structure, Electronic and Ionic Conductivities and Impedance Behavior of Y, Fe Co-Doped SrTiO3 Mixed Conductor

2018 ◽  
Vol 281 ◽  
pp. 774-781
Author(s):  
Ke Shan ◽  
Feng Rui Zhai ◽  
Nan Li ◽  
Zhong Zhou Yi
Keyword(s):  
Electrical Conductivity ◽  
Ionic Conductivity ◽  
Ionic Conduction ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Wide Frequency Range ◽  
Mixed Conductor ◽  
Doping Amount ◽  
Impedance Characteristics ◽  
Sol Gel Synthesis

A single phase perovskite, YxSr1−xTi0.6Fe0.4O3-δ(x=0.06-0.09), was fabricated at 1350°C in air by sol-gel method. The effects of Y-and Fe-doping into SrTiO3on phase structure, electrical conductivity, ionic conductivity and its impedance behavior were investigated. The optimized Y0.07Sr0.93Fe0.4Ti0.6O3-δsample exhibits an electrical conductivity of 0.135 S·cm-1at 800 °C. Y-doping decreases the migration energy for oxygen ions, leading to a significant increase in ionic conductivity. The ionic conductivity of Y0.09Sr0.91Ti0.6Fe0.4O3-δsample varies from 0.0052 S· cm-1at 600°C to 0.02 S·cm-1at 800°C. Impedance characteristics over a wide frequency range of 0.01Hz-100 KHz reveal that the resistance of ionic conduction is predominantly influenced by grain boundary, the relaxation time of which decreases with increase of Y-doping amount.

Sol-Gel Non-hydrolytic Synthesis of a Nanocomposite Electrolyte for Application in Lithium-ion Devices

2004 ◽  
Vol 822 ◽  
Author(s):  
Flávio L. Souza ◽  
Paulo R. Bueno ◽  
Ronaldo C. Faria ◽  
Elson Longo ◽  
Edson R. Leite
Keyword(s):  
Ionic Conductivity ◽  
Room Temperature ◽  
Sol Gel ◽  
Specific Treatment ◽  
Lithium Ion ◽  
Polymeric Chain ◽  
Conductivity Measurements ◽  
Ion Conductor ◽  
Nanocomposite Electrolyte ◽  
Excellent Reproducibility

AbstractA new nanocomposite electrolyte was synthesized using a simple non-hydrolytic sol-gel route without specific treatment of the reagents. The nanocomposite ion conductor was prepared with citric acid, tetraethyl orthosilicate and ethylene glycol, forming polyester chains. The time-consuming drying step that is a necessary part of most chemical syntheses was not required in the preparation of the present nanocomposite electrolyte of the polyelectrolyte class, because only Li+ is mobile in the polymeric chain. The effects of the concentration of Li, SiO 2 and SnO2nanoparticles were investigated in terms of Li+ ionic conductivity. Conductivity measurements as a function of the metal oxide nanocrystal content in the nanocomposite revealed a significant increase in conductivity at approximately 5 and 10 wt % of nanoparticles. The new nanocomposite conductor proved to be fully amorphous at room temperature, with a vitreous transition temperature of approximately 228K (−45°C). The material is solid and transparent, displaying an ionic conductivity of 10−4to 10−5 (O.cm)−1at room temperature presenting excellent reproducibility of all these characteristics. Cyclic voltammetry measurements indicate that the hybrid electrolyte possesses outstanding electrochemical stability.

scholarly journals Comparison of the Ionic Conductivity Properties of Microporous and Mesoporous MOFs Infiltrated with a Na-Ion Containing IL Mixture

2020 ◽  
Author(s):  
Joshua Tuffnell ◽  
Jędrzej K. Morzy ◽  
Rui Tan ◽  
Qilei Song ◽  
Caterina Ducati ◽  
...  
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Electrochemical Impedance ◽  
Metal Organic Framework ◽  
Sol Gel ◽  
Ionic Conductivities ◽  
Zeolitic Imidazolate Framework ◽  
Hierarchically Porous ◽  
Framework Materials ◽  
Sol Gel Synthesis

IL@MOF (IL: ionic liquid; MOF: metal-organic framework) materials have been proposed as a candidate for solid-state electrolytes, combining the inherent non-flammability and high thermal and chemical stability of the ionic liquid with the host-guest interactions of the MOF. In this work, we compare the structure and ionic conductivity of a sodium ion containing IL@MOF composite formed from a microcrystalline powder of the zeolitic imidazolate framework (ZIF), ZIF-8 with a hierarchically porous sample of ZIF-8 containing both micro- and mesopores from a sol-gel synthesis. Although the crystallographic structures were shown to be the same by X-ray diffraction, significant differences in particle size, packing and morphology were identified by electron microscopy techniques which highlight the origins of the hierarchical porosity. After incorporation of Na0.1EMIM0.9TFSI (abbreviated to NaIL; EMIM = 1-ethyl-3-methylimidazolium; TFSI = bis(trifluoromethylsulfonyl)imide), the hierarchically porous composite exhibited a 40 % greater filling capacity than the purely microporous sample which was confirmed by elemental analysis and digestive proton NMR. Finally, the ionic conductivity properties of the composite materials were probed by electrochemical impedance spectroscopy. The results showed that despite the 40 % increased loading of NaIL in the NaIL@ZIF-8micro sample, the ionic conductivities at 25 °C were 8.4x10-6 and 1.6x10-5 S cm-1 for NaIL@ZIF-8meso and NaIL@ZIF-8micro respectively. These results exemplify the importance of the long range, continuous ion pathways contributed by the microcrystalline pores, as well as the detrimental effect of discontinuous and tortuous mesoporous pathways which show a limited contribution to the overall ionic conductivity. <br>

Dielectric Behaviour Of BaTiO3 Prepared By Sol–Gel Technique When Exposed To Different Oxygen Concentrations

2012 ◽  
Author(s):  
Cheow Keat Yeoh ◽  
Srimala Sreekantan ◽  
Sabar Derita Hutagalung ◽  
Zainal Arifin Ahmad
Keyword(s):  
Dielectric Properties ◽  
Impedance Spectroscopy ◽  
Grain Boundary ◽  
Sol Gel ◽  
Chemical Processes ◽  
Oxygen Stoichiometry ◽  
Solution Ph ◽  
Gel Technique ◽  
Dta Curves ◽  
Oxygen Concentrations

Sifat dielektrik serbuk BaTiO3 yang disediakan melalui kaedah akues pada suhu rendah telah dikaji menggunakan kaedah spektroskopi impedans apabila didedahkan terhadap tahap oksigen yang berbeza. Untuk mengatasi masalah kebolehlarutan Ba dan Ti yang berbeza, nisbah sebatian Ba yang ditambah lebih tinggi daripada nisbah stoikiometri (tambahan 10%) dan nilai pH larutan yang tinggi (pH~13) diperlukan. Ujian XRD dan TGDTA menunjukkan BaTiO3 yang hampir tulen dapat disintesis melalui kaedah ini. Suhu pengkalsinan yang lebih tinggi menghasilkan darjah penghabluran bahan yang lebih tinggi. Kajian dielektrik menunjukkan bahan yang dihasilkan mengandungi lebih daripada satu elemen keelektrikan antaranya teras berkerintangan rendah, sempadan butiran berkapasitan tinggi dan suatu elemen pukal feroelektrik. Setelah didedahkan terhadap tahap oksigen yang lebih tinggi, nilai kerintangan sampel bertambah, yang mungkin disebabkan stoikiometri oksigen pada sampel yang diuji. Peningkatan dalam nilai kapasitan daripada sempadan butiran adalah lebih ketara jika dibandingkan dengan peningkatan unsur feroelektrik pukal. Kata kunci: Kaedah sol-gel, sintesis kimia, sifat dielektrik, BaTiO3 The dielectric properties of BaTiO3 powders prepared by a low temperature aqueous route when exposed to different oxygen concentrations have been studied by means of impedance spectroscopy. Due to the differences of solubility of Ba and Ti in aqueous solutions, deviations from stoichiometric ratios (a 10% excess) and higher solution pH (pH~13) were necessary. XRD traces and TG-DTA curves show the formation of nearly phase-pure BaTiO3 with higher calcinations temperatures promoting greater crystallinities. Dielectric measurements using impedance spectroscopy show the samples to consist of more than one electrical element including a low resistivity core, a high capacitance grain boundary and a ferroelectric bulk component. Exposing the samples to different oxygen concentrations caused a slight increase in resistivities with increasing oxygen concentration, which was attributed to the oxygen stoichiometry. A greater increase in the capacitance of the grain boundary component was also observed compared to the ferroelectric bulk. Key words: Sol-gel processes, chemical processes, dielectric properties, BaTiO3

Role of oxygen vacancy and Fe–O–Fe bond angle in compositional, magnetic, and dielectric relaxation on Eu-substituted BiFeO3 nanoparticles

2014 ◽  
Vol 43 (15) ◽  
pp. 5731-5738 ◽  
Author(s):  
A. Tamilselvan ◽  
S. Balakumar ◽  
M. Sakar ◽  
Chiranjib Nayek ◽  
P. Murugavel ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Oxygen Vacancy ◽  
Dielectric Relaxation ◽  
Oxygen Vacancies ◽  
Bond Angle ◽  
Sol Gel ◽  
Bifeo3 Nanoparticles ◽  
Gel Technique ◽  
Dielectric Relaxation Behavior

The influence of oxygen vacancies on the dielectric relaxation behavior of pure and Eu-substituted BiFeO3 nanoparticles synthesized by a sol–gel technique has been studied using impedance spectroscopy in the temperature range of 90 °C to 180 °C.

Sign in / Sign up

Export Citation Format

Share Document