The fate of aluminium in (Na,Bi)TiO3-based ionic conductors

2020 ◽  
Vol 8 (35) ◽  
pp. 18188-18197
Author(s):  
Pedro B. Groszewicz ◽  
Leonie Koch ◽  
Sebastian Steiner ◽  
Azatuhi Ayrikyan ◽  
Kyle G. Webber ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Ionic Conduction ◽  
Impedance Analysis ◽  
Ionic Conductors

The role of [AlTi–VO]˙ associated defects in ionic conduction in Al-doped (Na,Bi)TiO3 is clarified by a combination of impedance analysis, DFT calculations and NMR spectroscopy.

scholarly journals Bonding character and ionic conduction in solid electrolytes

2019 ◽  
Vol 91 (11) ◽  
pp. 1797-1806
Author(s):  
Masaru Aniya
Keyword(s):  
Ionic Conductivity ◽  
Ionic Conduction ◽  
Superionic Conductors ◽  
Ionic Conductors ◽  
Different Types ◽  
Medium Range ◽  
The Subject ◽  
Bond Fluctuation ◽  
Fluctuation Model

Abstract The properties of the materials are intimately related to the nature of the chemical bond. Research to explain the peculiarities of superionic materials by focusing on the bonding character of the materials is presented. In particular, a brief review of some fundamental aspects of superionic conductors is given based on the talk presented at “Solid State Chemistry 2018, Pardubice” in addition to some new results related to the subject. Specifically, the topics on bond fluctuation model of ionic conductors, the role of medium range structure in the ionic conductivity, bonding aspects of non-Arrhenius ionic conductivity and elastic properties of ionic conductors are discussed. Key concepts that are gained from these studies is stressed, such as the importance of the coexistence of different types of bonding, and the role of medium range structure in glasses for efficient ionic transport in solids. These concepts could help the development of new materials.

A transmission electron microscopic study of structural transitions in fast ionic conductors

1987 ◽  
Vol 45 ◽  
pp. 156-157
Author(s):  
R. B. Queenan ◽  
P. K. Davies
Keyword(s):  
Optical Properties ◽  
Ionic Conduction ◽  
Recent Observation ◽  
Ionic Conductivities ◽  
Sodium Aluminate ◽  
Two Dimensions ◽  
Ionic Conductors ◽  
Electron Microscopic ◽  
Transmission Electron ◽  
Trivalent Cations

Na ß“-alumina (Na1.67Mg67Al10.33O17) is a non-stoichiometric sodium aluminate which exhibits fast ionic conduction of the Na+ ions in two dimensions. The Na+ ions can be exchanged with a variety of mono-, di-, and trivalent cations. The resulting exchanged materials also show high ionic conductivities.Considerable interest in the Na+-Nd3+-ß“-aluminas has been generated as a result of the recent observation of lasing in the pulsed and cw modes. A recent TEM investigation on a 100% exchanged Nd ß“-alumina sample found evidence for the intergrowth of two different structure types. Microdiffraction revealed an ordered phase coexisting with an apparently disordered phase, in which the cations are completely randomized in two dimensions. If an order-disorder transition is present then the cooling rates would be expected to affect the microstructures of these materials which may in turn affect the optical properties. The purpose of this work was to investigate the affect of thermal treatments upon the micro-structural and optical properties of these materials.

γ-Valerolactone-Introduced Controlled-Isomerization of Glucose for Lactic Acid Production over Sn-Beta Catalyst

2021 ◽  
Author(s):  
Xinpeng Zhao ◽  
Zhimin Zhou ◽  
hu luo ◽  
Yanfei Zhang ◽  
Wang Liu ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Lactic Acid ◽  
Dft Calculations ◽  
Acid Production ◽  
Density Functional ◽  
Lactic Acid Production ◽  
Hydrothermal Conversion ◽  
Functional Theory ◽  
Environment Friendly

Combined experiments and density functional theory (DFT) calculations provided insights into the role of the environment-friendly γ-valerolactone (GVL) as a solvent in the hydrothermal conversion of glucose into lactic acid...

scholarly journals The Activating Effect of Strong Acid for Pd-Catalyzed Directed C–H Activation by Concerted Metalation-Deprotonation Mechanism

Molecules ◽  
2021 ◽  
Vol 26 (13) ◽  
pp. 4083
Author(s):  
Heming Jiang ◽  
Tian-Yu Sun
Keyword(s):  
Activation Energy ◽  
Dft Calculations ◽  
Energy Barrier ◽  
Computational Study ◽  
Strong Acid ◽  
Activation Energy Barrier ◽  
Pd Catalysts ◽  
Acid Ligand ◽  
Strong Acids

A computational study on the origin of the activating effect for Pd-catalyzed directed C–H activation by the concerted metalation-deprotonation (CMD) mechanism is conducted. DFT calculations indicate that strong acids can make Pd catalysts coordinate with directing groups (DGs) of the substrates more strongly and lower the C–H activation energy barrier. For the CMD mechanism, the electrophilicity of the Pd center and the basicity of the corresponding acid ligand for deprotonating the C–H bond are vital to the overall C–H activation energy barrier. Furthermore, this rule might disclose the role of some additives for C–H activation.

scholarly journals The role of hypervalent iodine(iii) reagents in promoting alkoxylation of unactivated C(sp3)–H bonds catalyzed by palladium(ii) complexes

2021 ◽  
Author(s):  
Payam Abdolalian ◽  
Samaneh K. Tizhoush ◽  
Kaveh Farshadfar ◽  
Alireza Ariafard
Keyword(s):  
Dft Calculations ◽  
Oxidative Addition ◽  
Hypervalent Iodine

This work uses DFT calculations to explore Pd(ii)-catalysed iodine(iii)-mediated alkoxylation of unactivated C(sp3)–H bonds and reveals how important the isomerization is in triggering the oxidative addition of ArIX2 to Pd(ii).

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

Role of Barium(II) in the Determination of the Absolute Configuration of Chiral Amines by1H NMR Spectroscopy

2006 ◽  
Vol 71 (3) ◽  
pp. 1119-1130 ◽  
Author(s):  
Rosa García ◽  
José M. Seco ◽  
Saulo A. Vázquez ◽  
Emilio Quiñoá ◽  
Ricardo Riguera
Keyword(s):  
Nmr Spectroscopy ◽  
Absolute Configuration ◽  
Chiral Amines ◽  
The Absolute

Fries Rearrangement of Aryl Formates:  A Mechanistic Study by Means of1H,2H, and11B NMR Spectroscopy and DFT Calculations

2006 ◽  
Vol 71 (25) ◽  
pp. 9331-9340 ◽  
Author(s):  
Alessandro Bagno ◽  
Willi Kantlehner ◽  
Ralf Kress ◽  
Giacomo Saielli ◽  
Edmont Stoyanov
Keyword(s):  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Mechanistic Study ◽  
Fries Rearrangement

CERAMICS BASED ON ORGANOSILICON POLYMERS-PRECURSORS: MICROSTRUCTURE AND PROPERTIES (review). Part 2

2021 ◽  
pp. 22-32
Author(s):  
A.M. Shestakov ◽  
Keyword(s):  
Electron Microscopy ◽  
Nmr Spectroscopy ◽  
Material Properties ◽  
Structural Organization ◽  
Ceramic Materials ◽  
Special Role ◽  
Correct Interpretation ◽  
Instrumental Methods ◽  
Organosilicon Polymers

Shows the scientific approaches of various authors to the study of the microstructure of ceramics, the purpose of which is to elucidate its structural organization at the micro- and nanoscale, as well as the influence of the microstructure on the complex of material properties. Various instrumental methods for studying ceramics (NMR spectroscopy, electron microscopy, х-ray structural analysis, etc.) are considered, the permissible capabilities of research methods and analysis of the results obtained with their correct interpretation are shown. The special role of theoretical modeling in understanding the structure of the considered ceramic materials is noted.

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