Synthesis, Structure, and Ionic Conductivity of K3NdSi6O15

1990 ◽  
Vol 210 ◽  
Author(s):  
Sossina M. Haile ◽  
Theo Siegrist ◽  
Robert A. Laudise ◽  
Bernhardt J. Wuensch
Keyword(s):  
Preexponential Factor ◽  
High Temperature Phase ◽  
Thermal Vibration ◽  
Temperature Phase ◽  
Hydrothermal Conditions ◽  
Ion Conductor ◽  
Composition And Structure ◽  
Fast Ion Conductor ◽  
Fast Ion ◽  
Reversible Phase

AbstractA structure earlier reported for K3NdSi6O15 suggests the possibility for fast—ion conduction by virtue of K+ ions which not only reside in connected channels, but which also display very large thermal vibration amplitudes. No properties of the phase had heretofore been examined. Crystals up to 2mm inlength have been synthesized under a variety of hydrothermal conditions. Refinement of the structure with single crystal x-ray data to a residual of 8.3% confirms the composition and structure of our crystals and reveals a very high thermal vibration amplitude along c for K+ ions which reside in interconnected [001] channels.A reversible phase transformation has been discovered at 180ºC with a heat of transformation of 4J/g. Preliminary measurements of the conductivity of the high temperature phase yield a preexponential factor of 3.4/cm and an activation energy of 0.61ev along [001], indicating that this compound is not a particularly good fast—ion conductor.

II. Electrical conductivity and phase transition studies on pure and doped (Cd2+, Gd3+)KNaSO4 and K3Na(SO4)2

1983 ◽  
Vol 61 (3) ◽  
pp. 599-601 ◽  
Author(s):  
M. Sunitha Kumari ◽  
Etalo A. Secco
Keyword(s):  
Phase Transition ◽  
Electrical Conductivity ◽  
High Temperature ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
Conductivity Measurements ◽  
Ion Conductor ◽  
Fast Ion Conductor ◽  
Fast Ion ◽  
Transition Studies

Electrical conductivity measurements on pure and doped KNaSO4 and K3Na(SO4)2 reveal high ionic conductivity values in the high temperature phase. High conductivity values ascribed to Na+ resemble a superionic or fast-ion conductor.

Unusual Fast Cation Conduction in the High-Temperature Phase of Lithium Sodium Sulfate

2002 ◽  
Vol 756 ◽  
Author(s):  
H. Feldmann ◽  
R. E. Lechner ◽  
D. Wilmer
Keyword(s):  
High Temperature ◽  
Sodium Sulfate ◽  
Correlation Factor ◽  
High Temperature Phase ◽  
Temperature Phase ◽  
60 Ghz ◽  
Tracer Transport ◽  
Ion Conductor ◽  
Fast Ion Conductor ◽  
A Charge

ABSTRACTLithium sodium sulfate (LiNaSO4) belongs to a group of simple inorganic salts exhibiting fast-cation conducting high-temperature phases with rotationally disordered anions. The analysis of a combination of quasielastic neutron scattering and high-frequency (10 MHz to 60 GHz) conductivity measurements in the high-temperature phase of LiNaSO4 reveals an unusual cation conduction mechanism: the Haven ratio, HR = D*/Dσ, turns out to be considerably larger than one. This behavior, to our knowledge detected for the first time in a typical fast ion conductor, can be traced back to a charge correlation factor clearly smaller than unity, indicating that charge transport is less effective than tracer transport in this material.

The thermodynamics of the divalent metal fluorides. I. Heat capacity of lead tetrafluorostannate, PbSnF4, from 10.3 to 352 K

1988 ◽  
Vol 66 (4) ◽  
pp. 549-552 ◽  
Author(s):  
Jane E. Callanan ◽  
Ron D. Weir ◽  
Edgar F. Westrum Jr.
Keyword(s):  
Phase Transition ◽  
Heat Capacity ◽  
Thermodynamic Functions ◽  
Adiabatic Calorimetry ◽  
Temperature Limit ◽  
Divalent Metal ◽  
Ion Conductor ◽  
Metal Fluorides ◽  
Fast Ion Conductor ◽  
Fast Ion

We have measured the heat capacity of the fast ion conductor PbSnF4 at 10.3 < T < 352 K by adiabatic calorimetry. Our results show anomalous values in the Cp,m in the region 300 < T < 352 K. These are associated with the α–β crystallographic transition reported at 353 K. Because the upper temperature limit of our cryostat is around 354 K, it was impossible to follow the phase transition to completion. A more subtle anomaly in the Cp,m was detected between 130 and 160 K. Standard molar thermodynamic functions are presented at selected temperatures from 5 to 350 K.

scholarly journals A Synthesis and Crystal Chemical Study of the Fast Ion Conductor Li7–3xGaxLa3 Zr2O12 with x = 0.08 to 0.84

2014 ◽  
Vol 53 (12) ◽  
pp. 6264-6269 ◽  
Author(s):  
Daniel Rettenwander ◽  
Charles A. Geiger ◽  
Martina Tribus ◽  
Peter Tropper ◽  
Georg Amthauer
Keyword(s):  
Chemical Study ◽  
Crystal Chemical ◽  
Ion Conductor ◽  
Fast Ion Conductor ◽  
Fast Ion

Preparation of β"-Alumina with η Type Nanometer Alumina Powder via Solid Phase Synthesis

2018 ◽  
Vol 281 ◽  
pp. 84-89
Author(s):  
Chao Zhang ◽  
Ling Zhang ◽  
Yan An Chang ◽  
Jin Han Liu
Keyword(s):  
Solid Phase ◽  
Synthesis Temperature ◽  
Alumina Powder ◽  
Mixed Powder ◽  
Ion Conductor ◽  
Amount Of Substance ◽  
Fast Ion Conductor ◽  
Fast Ion ◽  
Sulfur Battery ◽  
Beta Alumina

Beta”-alumina is a fast ion conductor material,it was uesd to prepare a new electrolyte for a secondary energy sodium sulfur battery. nanoeta-alumina has the advantages of high activity and small size,which can reduce the synthesis temperature of beta”-alumina. Beta”-alumina is prepared with Sodium carbonate and eta-alumina amount of substance ratio of 1:5.5 via solid phase synthesis.This paper mainly investigate the temperature on the influence of the content of beta”-alumina and the samples’ crystal structure.The samples were characterized by XRD and SEM.The results show that the mixed powder react to form rhombohedral beta”-alumina at 1100°C;the highest content of beta”-alumina is 87.26% at 1200°C;the beta”-alumina decompose and part of beta”-alumina gradually transform into hexagonal beta-alumina at 1300°C;the content of beta”-alumina reduce and the grain grow at 1400°C; particle of the sample grow irregular and its crystal morphology is incomplete at 1500°C.

Fast-ion conduction and local environments in BIMEVOX

2021 ◽  
Vol 379 (2211) ◽  
Author(s):  
Harry J. Stroud ◽  
Chris E. Mohn ◽  
Jean-Alexis Hernandez ◽  
Neil L. Allan
Keyword(s):  
Density Functional ◽  
Energy Landscape ◽  
Diffusion Mechanism ◽  
Ion Conduction ◽  
Functional Theory ◽  
Ion Conductor ◽  
Local Environments ◽  
Fast Ion Conductor ◽  
Fast Ion ◽  
Oxide Ions

The energy landscape of the fast-ion conductor Bi 4 V 2 O 11 is studied using density functional theory. There are a large number of energy minima, dominated by low-lying thermally accessible configurations in which there are equal numbers of oxygen vacancies in each vanadium–oxygen layer, a range of vanadium coordinations and a large variation in Bi–O and V–O distances. By dividing local minima in the energy landscape into sets of configurations, we then examine diffusion in each different layer using ab initio molecular dynamics. These simulations show that the diffusion mechanism mainly takes place in the 〈110〉 directions in the vanadium layers, involving the cooperative motion of the oxide ions between the O(2) and O(3) sites in these layers, but not O(1) in the Bi–O layers, in agreement with experiment. O(1) vacancies in the Bi–O layers are readily filled by the migration of oxygens from the V–O layers. The calculated ionic conductivity is in reasonable agreement with the experiment. We compare ion conduction in δ-Bi 4 V 2 O 11 with that in δ-Bi 2 O 3 . This article is part of the Theo Murphy meeting issue ‘Understanding fast-ion conduction in solid electrolytes’.

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