scholarly journals Syntheses and Characterization of Novel Perovskite-Type LaScO3-Based Lithium Ionic Conductors

Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 299
Author(s):  
Guowei Zhao ◽  
Kota Suzuki ◽  
Masaaki Hirayama ◽  
Ryoji Kanno
Keyword(s):  
Activation Energy ◽  
Ionic Conductivity ◽  
Structure Refinement ◽  
Compositional Analysis ◽  
Unit Cell ◽  
Phase Identification ◽  
Ionic Conductors ◽  
Co Doping ◽  
A Site ◽  
Perovskite Type

Perovskite-type lithium ionic conductors were explored in the (LixLa1−x/3)ScO3 system following their syntheses via a high-pressure solid-state reaction. Phase identification indicated that a solid solution with a perovskite-type structure was formed in the range 0 ≤ x < 0.6. When x = 0.45, (Li0.45La0.85)ScO3 exhibited the highest ionic conductivity and a low activation energy. Increasing the loading of lithium as an ionic diffusion carrier expanded the unit cell volume and contributed to the higher ionic conductivity and lower activation energy. Cations with higher oxidation numbers were introduced into the A/B sites to improve the ionic conductivity. Ce4+ and Zr4+ or Nb5+ dopants partially substituted the A-site (La/Li) and B-site Sc, respectively. Although B-site doping produced a lower ionic conductivity, A-site Ce4+ doping improved the conductive properties. A perovskite-type single phase was obtained for (Li0.45La0.78Ce0.05)ScO3 upon Ce4+ doping, providing a higher ionic conductivity than (Li0.45La0.85)ScO3. Compositional analysis and crystal-structure refinement of (Li0.45La0.85)ScO3 and (Li0.45La0.78Ce0.05)ScO3 revealed increased lithium contents and expansion of the unit cell upon Ce4+ co-doping. The highest ionic conductivity of 1.1 × 10−3 S cm−1 at 623 K was confirmed for (Li0.4Ce0.15La0.67)ScO3, which is more than one order of magnitude higher than that of the (LixLa1−x/3)ScO3 system.

The Structure of the γ′-Phase in Nickel-Base Superalloys

1965 ◽  
Vol 9 ◽  
pp. 131-141
Author(s):  
S. Rosen ◽  
P. G. Sprang
Keyword(s):  
Lattice Parameter ◽  
Unit Cell ◽  
Phase Identification ◽  
Carbide Phases ◽  
Intensity Measurements ◽  
Unit Cells ◽  
Nickel Base Superalloys ◽  
Face Centered ◽  
Nickel Base ◽  
Perovskite Type

AbstractPresent day nickel-base superalloys are hardened in part by the precipitation of a phase which has variously been identified as Ni3Al, Ni3(Al, Ti) and γ′. X-ray diffraction techniques which include precision lattice parameter measurements, intensity measurements, and phase identification are used to define the structural and chemical relationships upon which this phase is based.These relationships are developed from the following considerations: crystal chemistry and atomic size factors which relate binary Cu3Au-type T3B phases (e.g., Ni3Al) and ternary Perovskite-type T3BC2 carbide phases (e.g., Y3AlC), the determination of the number and kind of atoms in the unit cell of Ni3Al and certain ternary phases, the crystallographic relationship between the structure of Y3C and Y3AlC, and phase relations in certain quarternary alloys.From these considerations it is shown that the γ′ phase may best be characterized as a Peiovskite-type carbide phase having the chemical formula TsBCx. A model of the γ′ structure is presented which indicates the position of the various atomic constituents based upon whether they are T or B elements. (An atomic component is considered of the T type if it is capable of substituting for nickel in 3, of the B type if it can replace the aluminum. The essential features of this model are: T and B elements form an ordered T3B lattice of the Cu3Au type ; carbon atoms are located only in octahedral holes in the centers of the Cu3Au-type cells thereby establishing Perovskite-type T3BC3 unit cells; the effective size of T and B atoms in the T3BC3 unit cell is the same: hyperstoichiometric alloys, (ratio of B atoms to T atoms greater than one) will contain B atoms at face-centered positions in addition to a small amount of equilibrium vacant sites; in all alloys aluminum will preferentially occupy the cube corners of the unit cell ; the amount of carbon which is soluble in T3BC3; at any particular temperature is determined both by the distribution of the elements which are carbide-formers and the elements manganese, iron and cobalt. This model accounts for microstructural changes which occur in some nickel-base superalloys as a function of temperature and composition.

scholarly journals The Effect of Co-Doping at the A-Site on the Structure and Oxide Ion Conductivity in (Ba0.5−xSrx)La0.5InO3−δ: A Molecular Dynamics Study

Materials ◽  
2019 ◽  
Vol 12 (22) ◽  
pp. 3739
Author(s):  
Kuk-Jin Hwang ◽  
Hae-Jin Hwang ◽  
Myung-Hyun Lee ◽  
Seong-Min Jeong ◽  
Tae Shin
Keyword(s):  
Molecular Dynamics ◽  
Ionic Conductivity ◽  
Dynamics Simulation ◽  
Perovskite Oxide ◽  
Ion Conductor ◽  
Oxygen Ions ◽  
Co Doping ◽  
Oxide Ion Conductivity ◽  
Oxygen Ion Conductor ◽  
A Site

A molecular dynamics simulation was used to investigate the structural and transport properties of a (Ba0.5−xSrx)La0.5InO3−δ (x = 0, 0.1, 0.2) oxygen ion conductor. Previous studies reported that the ionic conductivity of Ba-doped LaInO3 decreases because Ba dopant forms a narrow oxygen path in the lattice, which could hinder the diffusion of oxygen ions. In this study, we reveal the mechanism to improve ionic conductivity by Ba and Sr co-doping on an La site in LaInO3 perovskite oxide. The results show that the ionic conductivity of (Ba0.5−xSrx)La0.5InO3−δ increases with an increasing number of Sr ions because oxygen diffusion paths which contain Sr ions have a larger critical radius than those containing Ba ions. The radial distribution function (RDF) calculations show that the peak heights in compositions including Sr ions were lower and broadened, meaning that the oxygen ions moved easily into other oxygen sites.

Predominant Factors of Lithium Ion Conductivity in Perovskite-Type Oxides

1996 ◽  
Vol 453 ◽  
Author(s):  
Y. Inaguma ◽  
T. Katsumata ◽  
J. Yu ◽  
M. Itoh
Keyword(s):  
Activation Energy ◽  
Lithium Ion ◽  
Ion Conductivity ◽  
Ion Conduction ◽  
Lithium Ion Conductivity ◽  
A Site ◽  
Perovskite Type

AbstractThe relation between the structure and the lithium ion conductivity in perovskite-type oxides ABO3 was investigated from the viewpoint of the the arrangement of A-site ions. It was showed that the conductivity in La2/3-xLi3x□1/3–2xTiO3 is strongly influenced by not only the concentration but also the ordered arrangement of skeletal A-site ions. Further the activation energy for ion conduction was found to be dominated by the covalency of B-O bond in addition to the bottleneck size.

scholarly journals Tailoring the Activation Energy and the Ionic Properties of Bismuth co-doped SDC Powder Prepared by Solid State Reaction Method

2021 ◽  
Author(s):  
Sandhya Kottooli ◽  
N.S. Chitra Priya ◽  
J.S. Revathy ◽  
Deepthi N. Rajendran ◽  
T. Praveen
Keyword(s):  
Activation Energy ◽  
Solid State ◽  
Ionic Conductivity ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Fluorite Structure ◽  
Solid State Reaction Method ◽  
Nyquist Plot ◽  
Reaction Method ◽  
Co Doped

Abstract Research on fuel cell components has received great attention owing to the growing need for sustainable energy sources. Bismuth (Bi 3+ ) co-doped samarium doped cerium oxide [Ce 1-x Sm x-y Bi y O 2-δ (x=0.2 and y=0, 0.05 and 0.1)] nanosystems were prepared by solid state reaction method. Rietveld structure refinement of X-ray diffraction pattern confirms the cubic fluorite structure along the (111) plane with the decrease in lattice distortion. At the same sintering temperature, pellets exhibit good morphology with better mechanical strength. The conductivity measurements carried out using the Nyquist plot, as well as the modulus spectra, indicate the effect of grain and grain boundary conduction at high temperatures. With the increase in the incorporation of Bi dopant, there is a gradual decrease in ionic conductivity and activation energy. The composition of Ce 0.8 Sm 0.1 Bi 0.1 O 2-δ exhibits less ionic conductivity compared to other samples due to the oxygen vacancies attracted by dopant cations. The effect of Bi 3+ dopants on samarium doped ceria lattice structures and the electrical properties of the systems has been discussed.

Influence of B-site ion valence on ion conduction for perovskite-type Li ion conductor, (La2/3–1/3p Lip)(Mg1/2W1/2)O3 (p =0.05, 0.11 and 0.14)

2004 ◽  
Vol 835 ◽  
Author(s):  
Tetsuhiro Katsumata ◽  
Megumi Takahata ◽  
Nobuko Mochizuki ◽  
Yoshiyuki Inaguma
Keyword(s):  
Activation Energy ◽  
Coulomb Repulsion ◽  
Ion Conductivity ◽  
Ion Conduction ◽  
Ion Conductor ◽  
Li Ion ◽  
A Site ◽  
Perovskite Type

AbstractWe synthesized perovskite-type Li ion conductor, (La2/3–1/3p Lip)(Mg1/2W1/2)O3 (p =0.05, 0.11 and 0.14), and investigated the variation of the Li ion conductivity with p. Furthermore, the variation of the activation energy with the valence of B-site ion was elucidated from the site potential at A-site and a bottleneck position. As results, it is suggested that the Coulomb repulsion between B-site and Li ions at the bottleneck dominates the activation energy for (La2/3–1/3p Lip)(Mg1/2W1/2)O3.

scholarly journals The Effect of Co-Doping at the A-Site on the Structure and Oxide Ion Conductivity in (Ba0.5-xSrx)La0.5InO3-δ: A Molecular Dynamics Study

2019 ◽  
Author(s):  
Kuk-Jin Hwang ◽  
Hae-Jin Hwang ◽  
Myung-Hyund Lee ◽  
Seng-Min Jeong ◽  
Tae Ho Shin
Keyword(s):  
Molecular Dynamics ◽  
Ionic Conductivity ◽  
Dynamics Simulation ◽  
Perovskite Oxide ◽  
Ion Conductor ◽  
Co Doping ◽  
Oxide Ion Conductivity ◽  
Oxygen Ion ◽  
Oxygen Ion Conductor ◽  
A Site

The molecular dynamics simulation has been used to investigate the structural and transport properties of (Ba0.5-xSrx)La0.5InO3-&delta; (x=0, 0.1, 0.2) oxygen-ion conductor. The previous studies reported that the ionic conductivity of Ba-doped LaInO3 decreases because Ba dopant forms narrow oxygen path in the lattice, which could hinder the diffusion of oxygen ion. In this study, we reveal the mechanism to improve the ionic conductivity by Ba and Sr co-doping on La site in LaInO3 perovskite oxide. The results show that the ionic conductivity of (Ba0.5-xSrx)La0.5InO3-&delta; increases with increasing numbers of Sr ions, which oxygen diffusion paths including Sr ion have larger critical radius than Ba ions. The RDF calculations showed the heights of peak in composition including Sr ions is lower and broaden, so oxygen ions moved easily into other oxygen sites.

scholarly journals CO Oxidation Capabilities of La- and Nd-Based Perovskites

Fuels ◽  
2022 ◽  
Vol 3 (1) ◽  
pp. 31-43
Author(s):  
Thomas Ruh ◽  
Richard Buchinger ◽  
Lorenz Lindenthal ◽  
Florian Schrenk ◽  
Christoph Rameshan
Keyword(s):  
Co Oxidation ◽  
Ignition Temperature ◽  
Heterogeneous Catalysts ◽  
Catalyst Design ◽  
Co Doping ◽  
Interesting Approach ◽  
Material Choice ◽  
A Site ◽  
Perovskite Type

Catalytic tests to assess the performance of mixed perovskite-type oxides (La0.9Ca0.1FeO3-δ, La0.6Ca0.4FeO3-δ, Nd0.9Ca0.1FeO3-δ, Nd0.6Ca0.4FeO3-δ, Nd0.6Ca0.4Fe0.9Co0.1O3-δ, Nd0.6Ca0.4Fe0.97Ni0.03O3-δ, and LSF) with respect to CO oxidation are presented as well as characterization of the materials by XRD and SEM. Perovskites are a highly versatile class of materials due to their flexible composition and their ability to incorporate dopants easily. CO oxidation is a widely used “probe reaction” for heterogeneous catalysts. In this study, it is demonstrated how tuning the composition of the catalyst material (choice of A-site cation, A-site and B-site doping) greatly influences the activity. Changing the A-site cation to Nd3+ or increasing the concentration of Ca2+ as A-site dopant improves the performance of the catalyst. Additional B-site doping (e.g., Co) affects the performance as well—in the case of Co-doping by shifting ignition temperature to lower temperatures. Thus, perovskites offer an interesting approach to intelligent catalyst design and tuning the specific properties towards desired applications.

X-ray Structure Refinement and Vibrational Spectroscopy of Ca8Gd2 (PO4)6 O2

2013 ◽  
Vol 12 (10) ◽  
pp. 719-726
Author(s):  
R. Ayadi ◽  
Mohamed Boujelbene ◽  
T. Mhiri
Keyword(s):  
Solid State ◽  
General Formula ◽  
Vibrational Spectroscopy ◽  
Powder Diffraction ◽  
Infrared Spectra ◽  
Solid State Reaction ◽  
Structure Refinement ◽  
Unit Cell ◽  
Cell Group ◽  
X Ray

The present paper is interested in the study of compounds from the apatite family with the general formula Ca10 (PO4)6A2. It particularly brings to light the exploitation of the distinctive stereochemistries of two Ca positions in apatite. In fact, Gd-Bearing oxyapatiteCa8 Gd2 (PO4)6O2 has been synthesized by solid state reaction and characterized by X-ray powder diffraction. The site occupancies of substituents is0.3333 in Gd and 0.3333 for Ca in the Ca(1) position and 0. 5 for Gd in the Ca (2) position.  Besides, the observed frequencies in the Raman and infrared spectra were explained and discussed on the basis of unit-cell group analyses.

How Certain Are the Reported Ionic Conductivities of Thiophosphate-Based Solid Electrolytes? an Interlaboratory Study

2020 ◽  
Author(s):  
Saneyuki Ohno ◽  
Tim Bernges ◽  
Johannes Buchheim ◽  
Marc Duchardt ◽  
Anna-Katharina Hatz ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Ionic Conductivity ◽  
Relative Standard Deviation ◽  
Solid Electrolytes ◽  
Ionic Conductivities ◽  
Ionic Conductors ◽  
Energy Storage Devices ◽  
Activation Barriers ◽  
Storage Devices ◽  
Relative Standard

<p>Owing to highly conductive solid ionic conductors, all-solid-state batteries attract significant attention as promising next-generation energy storage devices. A lot of research is invested in the search and optimization of solid electrolytes with higher ionic conductivity. However, a systematic study of an <i>interlaboratory reproducibility</i> of measured ionic conductivities and activation energies is missing, making the comparison of absolute values in literature challenging. In this study, we perform an uncertainty evaluation via a Round Robin approach using different Li-argyrodites exhibiting orders of magnitude different ionic conductivities as reference materials. Identical samples are distributed to different research laboratories and the conductivities and activation barriers are measured by impedance spectroscopy. The results show large ranges of up to 4.5 mScm<sup>-1</sup> in the measured total ionic conductivity (1.3 – 5.8 mScm<sup>-1</sup> for the highest conducting sample, relative standard deviation 35 – 50% across all samples) and up to 128 meV for the activation barriers (198 – 326 meV, relative standard deviation 5 – 15%, across all samples), presenting the necessity of a more rigorous methodology including further collaborations within the community and multiplicate measurements.</p>

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