Large Cation Model of Dissociative Reduction of WO3-x Lattice Studied by EQCN and AFM

2019 ◽  
Vol 19 (23) ◽  
pp. 11-23 ◽  
Author(s):  
Maria Hepel ◽  
David Wickham
Keyword(s):  
Large Cation

Ferroelectricity, ionic conductivity and structural paths for large cation migration in Ca10.5−xPbx(VO4)7 single crystals, x = 1.9, 3.5, 4.9

CrystEngComm ◽  
2019 ◽  
Vol 21 (8) ◽  
pp. 1309-1319 ◽  
Author(s):  
Dina V. Deyneko ◽  
Daria A. Petrova ◽  
Sergey M. Aksenov ◽  
Sergey Yu. Stefanovich ◽  
Oksana V. Baryshnikova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Optical Properties ◽  
Ionic Conductivity ◽  
Single Crystals ◽  
Cation Migration ◽  
Non Linear ◽  
Linear Optical Properties ◽  
Linear Optical ◽  
Large Cation

Crystal structure, thermal, ionic conductivity of large cations (Ca and Pb), dielectric and non-linear optical properties were investigated for Ca10.5−xPbx(VO4)7 single crystals (x = 1.9, 3.5, 4.9).

Large Cation−Anion Materials Based on Trinuclear Ruthenium(III) Salts of Keggin and Wells-Dawson Anions Having Water-Filled Channels

2009 ◽  
Vol 48 (4) ◽  
pp. 1649-1654 ◽  
Author(s):  
Masooma Ibrahim ◽  
Michael H. Dickman ◽  
Andreas Suchopar ◽  
Ulrich Kortz
Keyword(s):  
Large Cation

Effect of Associated Salts on the Polymerization of Butadiene by Organosodium Reagents

1953 ◽  
Vol 26 (3) ◽  
pp. 543-558
Author(s):  
Avery A. Morton ◽  
Frank H. Bolton ◽  
Frances W. Collins ◽  
Edward F. Cluff
Keyword(s):  
Emulsion Polymerization ◽  
Lithium Ion ◽  
Sodium Cation ◽  
Lithium Salts ◽  
Lithium Iodide ◽  
Sodium Salts ◽  
Cesium Fluoride ◽  
Iodine Chloride ◽  
Sodium And Potassium ◽  
Large Cation

Abstract The alfin catalyst is a combination of sodium salts which causes butadiene to polymerize at extreme rapidity in such a fashion that a greater difference exists between sodium and alfin polymerization than between sodium and emulsion polymerization. Hitherto the combination has been assumed to be binary—allylsodium and sodium isopropoxide—but a new method of preparation has revealed that a halide or pseudohalide salt is essential. Chloride, bromide, and iodide salts of sodium and potassium can be used as the halide component, but fluoride and lithium salts, as a rule, cannot be so employed unless the small size of each ion is compensated by a large cation or anion, respectively, as found in cesium fluoride or lithium iodide. The sodium cation is required for the catalyst. The potassium ion can be tolerated in the alkoxide or halide, but not simultaneousely in both. The lithium ion is in general unsuitable. Alfin polybutadiene is differentiated from sodium-polymerized butadiene by a high proportion of 1,4-structure and by an abnormally high intrinsic viscosity. Iodine chloride causes the polymer to precipitate from solution. All results indicate that polymerization by sodium reagents is in considerable degree controlled by the association of other salts with the sodium reagent.

Large cation-selective pores from rat liver peroxisomal membranes incorporated to planar lipid bilayers

1986 ◽  
Vol 94 (3) ◽  
pp. 285-291 ◽  
Author(s):  
Pedro Labarca ◽  
Daniel Wolff ◽  
Ubaldo Soto ◽  
Cecilia Necochea ◽  
Federico Leighton
Keyword(s):  
Lipid Bilayers ◽  
Rat Liver ◽  
Planar Lipid Bilayers ◽  
Large Cation

On the crystal structures of some nickel hexacyanoferrates (II,III)

2004 ◽  
Vol 19 (3) ◽  
pp. 284-291 ◽  
Author(s):  
R. Martínez-Garcia ◽  
E. Reguera ◽  
J. Balmaseda ◽  
G. Ramos ◽  
H. Yee-Madeira
Keyword(s):  
Aqueous Solution ◽  
Crystal Structures ◽  
Interstitial Water ◽  
Structural Information ◽  
Water Molecules ◽  
Ionic Exchange ◽  
Orthorhombic Distortion ◽  
Orthorhombic Space Group ◽  
Space Group ◽  
Large Cation

The crystal structures of some nickel hexacyanoferrates (II, III), including mixed compositions containing Na+, K+ and Cs+, were resolved and refined from XRD powder patterns. Data from infrared, Mössbauer and adsorption techniques provided complementary structural information. The crystal structures of Ni3[Fe(CN)6]2⋅16H2O and NiCs2[Fe(CN)6] were refined in space group Fm3m. NiNa2[Fe(CN)6]⋅2H2O and NiK2[Fe(CN)6]⋅2H2O were found to be orthorhombic (space group Pmn21). This structure (Pmn21) results from a distortion around the alkali ion, which appears as a monohydrated interstitial species. On ionic exchange in an aqueous solution containing Cs+, the orthorhombic distortion disappears and the cubic cell is obtained. Cs+ is a large cation and space is not available for interstitial water molecules. This orthorhombic model is also supported by the Mössbauer spectra of the ferrous analogs, FeK2[Fe(CN)6]⋅xH2O and Fe[Pt(CN)6]. © 2004 International Centre for Diffraction Data.

Catalytic Combustion of Methane Over Metal Oxide Catalysts

1998 ◽  
Vol 549 ◽  
Author(s):  
Koichi Eguchi ◽  
Hiroyuki Takahara ◽  
Hiroshi Inoue ◽  
Koshi Sekizawa
Keyword(s):  
Catalytic Activity ◽  
Catalytic Combustion ◽  
Ionic Radius ◽  
Structural Effect ◽  
Mirror Plane ◽  
Cation Substitution ◽  
Redox Cycle ◽  
Ionic Radii ◽  
Catalytic Combustion Of Methane ◽  
Large Cation

AbstractCation-substituted hexaaluminate compounds, ABAl11O19-μ (A = La, Pr, Sm, and Nd; B = Cr, Mn, Fe, Co, Ni, and Cu) were investigated for application to high temperature catalytic combustion. Two series of modifications of the compounds was made by cation substitution; substitution of large cations in the mirror plane with lanthanides ions, and of transition metals for Al site in the spinel block. In a series of AMnAlllO19-μ, surface area and catalytic activity increased with an increase in ionic radius of lanthanides. La3+ is superior as the large cation in the mirror plane of the hexaaluminate to other tri-valent cations with small ionic radii. The catalytic activi- ties of LaBAl11O19-μ, were enhanced when Mn and Cu were employed as the B-site substituents. Although Mn and Cu were also effective substituents for enhancing catalytic activity in Ba-based hexaaluminate compounds, their activity was low as compared with the La-based catalysts. These results indicate that the redox cycle of transition metal in hexaaluminate lattice and cata- lytic activity appears to be affected sensitively with the electronic or structural effect of large cation in the mirror plane.

scholarly journals The interaction of cations with the dye arsenazo III

1989 ◽  
Vol 259 (1) ◽  
pp. 295-298 ◽  
Author(s):  
E Rowatt ◽  
R J P Williams
Keyword(s):  
Metal Cations ◽  
Absorption Peak ◽  
Arsenazo Iii ◽  
Single Atom ◽  
Extended Form ◽  
Cobalt Ions ◽  
Bivalent Cations ◽  
Large Cation ◽  
Selection Of ◽  
Dye Molecule

1. The dye arsenazo III combines with a selection of cations to give an altered absorption spectrum. 2. Large metal cations such as Ca2+, La3+ and quadrivalent cations give a 1:1 complex with two new absorption peaks at about 610 nm and 655 nm and a KD of about 10(-6) M. 3. Aliphatic polyamines and complex cobalt ions give a 1:1 complex, with one absorption peak at about 610 nm and a KD from 10(-6) to 10(-3) M. 4. Small metal cations finally form a 2:1 complex and also have one absorption peak at about 610 nm, but with a KD of 10(-5)-10(-4) M. 5. The absorption peak at 610 nm is similar to that formed at high pH in the absence of bivalent cations and is due to ionization of phenolic groups with the dye molecule in an extended form. 6. The peak at 655 nm with 1:1 complex can be explained as a change in orientation of the diazo bonds caused by a conformational change of the molecule when it wraps around the single atom of Ca2+ or other large cation.

PHASE SEPARATION INDUCED BY CATION DISORDER IN (La, Y)2/3(Sr, Ca)1/3MnO3

2011 ◽  
Vol 25 (11) ◽  
pp. 1501-1509
Author(s):  
A. M. ZHANG ◽  
H. L. CAI ◽  
X. S. WU ◽  
Z. H. WANG ◽  
J. GAO
Keyword(s):  
Phase Separation ◽  
Hole Concentration ◽  
Transition Width ◽  
Cation Disorder ◽  
Metal To Insulator Transition ◽  
Metal State ◽  
Phase Separation Behavior ◽  
A Site ◽  
Separation Behavior ◽  
Large Cation

Polycrystalline manganite oxides with different A-site cation disorder were synthesized. The hole concentration and average radius of A-site cation are kept unchanged while the A-site cation disorder increases linearly by Y and Sr co-doped in La 2/3 Ca 1/3 MnO 3. All these samples exhibit a paramagnetic insulator to ferromagnetic (FM) metal transition, and the transition temperature T C and T MI decrease while the transition width increases with increasing the A-site cation disorder. T MI is usually 10 K higher than T C for the small cation disorder samples. However, with increasing the cation disorder, T MI is about 60 K lower than T C , and the resistivity increases in magnitude while the magnetization decreases. The metal-to-insulator transition for samples with small cation disorder can be well described by a percolative model, which indicates FM-metal state and antiferromagnetic insulator state assuredly coexist in the transition interval. It reveals that cation disorder suppresses the long-range FM-metal state which results in the phase separation behavior in samples with large cation disorder.

Large Cation Engineering in Two-Dimensional Silver–Bismuth Bromide Double Perovskites

2021 ◽  
Author(s):  
Fabian Schmitz ◽  
Jonas Horn ◽  
Nicola Dengo ◽  
Alexander E. Sedykh ◽  
Jonathan Becker ◽  
...  
Keyword(s):  
Double Perovskites ◽  
Two Dimensional ◽  
Large Cation
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