scholarly journals Small Ionic Radius Limits Magnesium Water Interaction in Amorphous Calcium/Magnesium Carbonates

2020 ◽  
Vol 124 (11) ◽  
pp. 6141-6144 ◽  
Author(s):  
Anders C. S. Jensen ◽  
Silvia Imberti ◽  
Wouter J.E.M. Habraken ◽  
Luca Bertinetti
Keyword(s):  
Ionic Radius ◽  
Water Interaction ◽  
Small Ionic Radius ◽  
Calcium Magnesium

scholarly journals Theoretical prediction by DFT and experimental observation of heterocation-doping effects on hydrogen adsorption and migration over the CeO2(111) surface

2021 ◽  
Author(s):  
Kota Murakami ◽  
Yuta Mizutani ◽  
Hiroshi Sampei ◽  
Atsushi Ishikawa ◽  
Yuta Tanaka ◽  
...  
Keyword(s):  
Theoretical Prediction ◽  
Experimental Observation ◽  
Ionic Radius ◽  
Hydrogen Adsorption ◽  
Strong Binding ◽  
Doping Effects ◽  
Small Ionic Radius ◽  
And Migration

The addition of dopants with a small ionic radius led to strong binding of H atoms, and the balance of H+ reactivity (mobility) and H+ coverage was fundamentally important for high H+ conductivity and catalysis involving surface protonics.

Magnetoelectric and magnetoelastic properties of easy-plane ferroborates with a small ionic radius

2012 ◽  
Vol 114 (5) ◽  
pp. 810-817 ◽  
Author(s):  
A. M. Kadomtseva ◽  
G. P. Vorob’ev ◽  
Yu. F. Popov ◽  
A. P. Pyatakov ◽  
A. A. Mukhin ◽  
...  
Keyword(s):  
Ionic Radius ◽  
Easy Plane ◽  
Magnetoelastic Properties ◽  
Small Ionic Radius

scholarly journals Pr- and Sm-Substituted Layered Perovskite Oxide Systems for IT-SOFC Cathodes

Energies ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6739
Author(s):  
Sung Hun Woo ◽  
Kyeong Eun Song ◽  
Seung-Wook Baek ◽  
Hyunil Kang ◽  
Wonseok Choi ◽  
...  
Keyword(s):  
Solid Oxide Fuel Cells ◽  
Ionic Radius ◽  
Perovskite Oxide ◽  
Layered Perovskite ◽  
Oxide Systems ◽  
Phase Synthesis ◽  
Small Ionic Radius ◽  
Temperature Operating ◽  
A Site ◽  
Layered Perovskites

In this study, the phase synthesis and electrochemical properties of A/A//A///B2O5+d (A/: Lanthanide, A//: Ba, and A//: Sr) layered perovskites in which Pr and Sm were substituted at the A/-site were investigated for cathode materials of Intermediate Temperature-Operating Solid Oxide Fuel cells (IT-SOFC). In the PrxSm1-xBa0.5Sr0.5Co2O5+d (x = 0.1–0.9) systems, tetragonal (x < 0.4) and orthorhombic (x ≥ 0.5) crystalline structures were confirmed according to the substitution amount of Pr, which has a relatively large ionic radius, and Sm, which has a small ionic radius. All of the layered perovskite oxide systems utilized in this study presented typical metallic conductivity behavior, with decreasing electrical conductivity as temperature increased. In addition, Pr0.5Sm0.5Ba0.5Sr0.5Co2O5+d (PSBSCO55), showing a tetragonal crystalline structure, had the lowest conductivity values. However, the Area-Specific Resistance (ASR) of PSBSCO55 was found to be 0.10 Ωcm2 at 700 °C, which is lower than those of the other compositions.

Effects of dopant concentration on the microstructure of tin- doped indium oxide thin films

1990 ◽  
Vol 48 (4) ◽  
pp. 716-717
Author(s):  
I. A. Rauf
Keyword(s):  
Thin Films ◽  
Indium Oxide ◽  
Ionic Radius ◽  
Free Carrier ◽  
Electron Gun ◽  
Periodic Lattice ◽  
Oxide Thin Films ◽  
Transmission Electron ◽  
The Difference ◽  
Dopant Atoms

To understand the electronic conduction mechanism in Sn-doped indium oxide thin films, it is important to study the effect of dopant atoms on the neighbouring indium oxide lattice. Ideally Sn is a substitutional dopant at random indium sites. The difference in valence (Sn4+ replaces In3+) requires that an extra electron is donated to the lattice and thus contributes to the free carrier density. But since Sn is an adjacent member of the same row in the periodic table, the difference in the ionic radius (In3+: 0.218 nm; Sn4+: 0.205 nm) will introduce a strain in the indium oxide lattice. Free carrier electron waves will no longer see a perfect periodic lattice and will be scattered, resulting in the reduction of free carrier mobility, which will lower the electrical conductivity (an undesirable effect in most applications).One of the main objectives of the present investigation is to understand the effects of the strain (produced by difference in the ionic radius) on the microstructure of the indium oxide lattice when the doping level is increased to give high carrier densities. Sn-doped indium oxide thin films were prepared with four different concentrations: 9, 10, 11 and 12 mol. % of SnO2 in the starting material. All the samples were prepared at an oxygen partial pressure of 0.067 Pa and a substrate temperature of 250°C using an Edwards 306 coating unit with an electron gun attachment for heating the crucible. These deposition conditions have been found to give optimum electrical properties in Sn-doped indium oxide films. A JEOL 2000EX transmission electron microscope was used to investigate the specimen microstructure.

The Steam Explosion Induced by the Molten Reactor Material-Water Interaction

2002 ◽  
Author(s):  
J. H. Song ◽  
I. K. Park ◽  
Yongseung Shin ◽  
J. H. Kim ◽  
S.W. Hong ◽  
...  
Keyword(s):  
Steam Explosion ◽  
Reactor Material ◽  
Water Interaction

Formation of water chemistry in the Modonkul river under the action of mine drainage effluent

2020 ◽  
pp. 56-66
Author(s):  
Z. I. Khazheeva ◽  
S. S. Sanzhanova
Keyword(s):  
Water Chemistry ◽  
Mine Drainage ◽  
High Concentration ◽  
Catchment Basin ◽  
Sulfate Anion ◽  
Concentrated Flow ◽  
Sodium Calcium ◽  
Calcium Cation ◽  
Calcium Magnesium ◽  
The Town

The Dzhida ore field in the Zakamensk district of Buryatia features high concentration of mineralization within a small area. The Dzhida deposit is composed of complex ore. The ore field contains commercial-value primary deposits: Pervomai stockwork of molybdenum, Kholtoson tungsten lode and Inkur stockwork of tungsten. The Modonkul river catchment basin lies inside the Dzhida ore field. A real threat to the town of Zakamensk is created by manmade sand-bulk (old) tailings and slurry dump. By now, the concentrated flow of natural and man-made sand enters the low terrace and floodplain of the Modonkul river in the form of a talus train. This study is focused on the influence of the mine drainage effluent and the Inkur tributary on the water chemistry in the Modonkul river. 80 water samples were taken from the surface layer 0-0.5 m thick at five stations. Physicochemical indices of water were measured at the water sampling points, and the water chemistry was analyzed in a laboratory. In the background conditions, cations and anions in the Modonkul water chemistry range in decreasing order as follows: Са2+ > Mg2+ > Na++К+ и HCO - > SO 2- > Cl-. In the zone of mixture of natural and mine process water, the chemistry changes: from hydrocarbonate to sulfate (anion), from calcium-magnesium to sodium-calcium (cation). Downstream the natural chemistry changes to the hydrocabonate-sulfate composition, with prevailing content of calcium in cations. Iron content of water lowers 3-4 times after influx of mine effluents, while the contents of Mn, Zn, Co and Cd grow and then decrease downstream.

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