Ionic conductivity and mixed-ion effect in mixed alkali metaphosphate glasses

2017 ◽  
Vol 19 (9) ◽  
pp. 6594-6600 ◽  
Author(s):  
Jefferson Esquina Tsuchida ◽  
Fabio Aparecido Ferri ◽  
Paulo Sergio Pizani ◽  
Ana Candida Martins Rodrigues ◽  
Swarup Kundu ◽  
...  
Keyword(s):  
Ionic Conductivity ◽  
Experimental Evidence ◽  
Natural Consequence ◽  
Size Mismatch ◽  
Mixed Alkali ◽  
Cation Size

Experimental evidence has confirmed that the mixed-ion effect (MIE) can be explained as a natural consequence of random ion mixing and that the cation size mismatch is not the only factor that determines the intensity of MIE.

Cation-size mismatch and interface stabilization for efficient NiOx-based inverted perovskite solar cells with 21.9% efficiency

Nano Energy ◽  
2021 ◽  
pp. 106285
Author(s):  
Yousheng Wang ◽  
Hui Ju ◽  
Tahmineh Mahmoudi ◽  
Chong Liu ◽  
Cuiling Zhang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Size Mismatch ◽  
Cation Size

scholarly journals Structural and Electrical Properties of Ca2+ Doped LaFeO3: The Effect of A-site Cation Size Mismatch

2020 ◽  
Vol 10 (2) ◽  
pp. 5538-5546
Author(s):  
A. E. Irmak
Keyword(s):  
Crystal Structure ◽  
Sol Gel ◽  
Charge Ordering ◽  
Room Temperature Resistivity ◽  
Size Mismatch ◽  
Ca Doping ◽  
Average Size ◽  
A Site ◽  
Cation Size ◽  
Small Polarons

In this study, nanosized La1-xCaxFeO3 (0.00≤x≤0.40) compounds prepared via sol-gel method followed by heat treatment at 1100oC for 24 hours are studied. Crystal structure, microstructure, surface morphology and temperature-dependent resistivity of the samples are investigated. TEM investigation reveals nanoparticles with an average size of 35nm produced from the sol-gel process. The crystal structure of the compounds belongs to an orthorhombically distorted perovskite structure with Pbnm space group. Lattice distortion and cation size mismatch increase with an increase in Ca and particle and grain growth are suppressed by Ca doping. Electrical conduction is explained via thermally activated hopping of small polarons. Unit cell volume, charge ordering temperature, and activation energy for small polarons decrease linearly with an increase in cation size mismatch. Room temperature resistivity decreases with Ca doping and gets its minimum value for 30% Ca at which the orthorhombic distortion is maximum.

Structural Features and the Effect of Two Alkalis in Chalcogenide and Phosphate Glasses

2019 ◽  
Vol 822 ◽  
pp. 824-833
Author(s):  
Viktor A. Markov ◽  
Ivan Sokolov ◽  
Alexey Povolotskiy
Keyword(s):  
Ionic Conductivity ◽  
Electric Current ◽  
Structural Features ◽  
Phosphate Glasses ◽  
Electrical Parameters ◽  
Mixed Alkali ◽  
Mixed Alkali Effect

This paper presents data on the mixed alkali effect in two fundamentally different systems: chalcogenide and oxide (phosphate). In the first system (Ag – Cu)0.44AsSe1.5, the predominantly ionic conductivity of silver-containing glasses is replaced by purely electronic in copper-containing, in the second - 0.5(Li2O-Na2O) – 0.4P2O5 – 0.1Nb2O5 carriers of electric current are alkaline ions and the extreme dependences of the electrical parameters associated with their joint migration.

Cation-Size Mismatch as a Design Principle for Enhancing the Efficiency of Garnet Phosphors

2020 ◽  
Vol 32 (7) ◽  
pp. 3097-3108 ◽  
Author(s):  
Yoon Hwa Kim ◽  
Ha Jun Kim ◽  
Shyue Ping Ong ◽  
Zhenbin Wang ◽  
Won Bin Im
Keyword(s):  
Design Principle ◽  
Size Mismatch ◽  
Cation Size

The Mixed Alkali Effect in Sodium Rubidium Germanate Glasses

1985 ◽  
Vol 61 ◽  
Author(s):  
J. N. Mundy ◽  
G.-L. Jin
Keyword(s):  
Ionic Conductivity ◽  
Glass Network ◽  
Theoretical Models ◽  
General Applicability ◽  
Alkali Ions ◽  
Mixed Alkali ◽  
Mixed Alkali Effect ◽  
The Many ◽  
The Relationship ◽  
Germanate Glasses

ABSTRACTThe lack of general applicability of the many theoretical models for the mixed alkali effect (MAE) in glasses is briefly reviewed. Although the MAE appears to be related to the bonding affinity of alkali ions to charge compensating centers in the glass network, experimental scatter and the difficulty of comparing different glass networks have prevented systematic tests of this relationship. The present paper discusses why the mixed alkali germanate glasses should provide a glass system where the concentration and strength of charge-compensating centers can be systematically varied and the relationship to the MAE tested. Such tests are only possible if the ionic conductivity of a series of mixed alkali germanate glasses can be measured in a reproducible manner. The measurements of the ionic conductivity of two series of X(Na,Rb)2O:(1-X)GeO2 glasses, with X = 0.19 and X = 0.29, respectively, suggest the necessary reproducibility can be attained.

Ionic conductivity and solid phase transitions in Na2SO4–Cs2SO4 system

1988 ◽  
Vol 66 (12) ◽  
pp. 3132-3136 ◽  
Author(s):  
Kevin G. Macdonald ◽  
Charles Maclean ◽  
E. A. Secco
Keyword(s):  
Phase Transition ◽  
High Temperature ◽  
Ionic Conductivity ◽  
Solid Phase ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Mixed Alkali ◽  
Temperature Phase Transition ◽  
Decomposition Behavior ◽  
Hedvall Effect

The ac conductivity and DSC calorimetry data reveal interesting solid state interactions and solid phase transition behavior in the Na2SO4–Cs2SO4 binary system. The β → α solid transition of NaCsSO4 is reported for the first time. These data indicate preferential reaction between Cs2SO4 and the high temperature phase I of Na2SO4, exemplifying the Hedvall effect, to form the compound NaCsSO4 which further interacts with excess Na2SO4 or excess Cs2SO4 to form 1:1 association complexes, viz. NaCsSO4:Na2SO4 and NaCsSO4:Cs2SO4. These complexes appear to dissociate at low temperatures reminiscent of spinodal-type decomposition behavior. The reaction enthalpies of NaCsSO4, β → α transition of NaCsSO4 and complex associations are reported.The report contains two unexpected results: (i) a subdued higher ionic conductivity relative to its Rb2SO4 analogue and (ii) a conductivity drop accompanying the high temperature phase transition which is in strong contrast to all the other Na2SO4 – mixed alkali compositions.

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