Showing papers on "Ionic conductivity published in 1978"
TL;DR: Li 16−2x D x (TO 4 ) 4, where D is a divalent cation and T is a tetravalent cation, has a resistivity of 8 ω-cm at 300°C, lower than that of any Li + -ion conductor so far reported.
439 citations
TL;DR: In this paper, a molecular-dynamcis study of silver diffusion in superionic conductor AgI is performed, where the potentials are constructed using Pauling's ideas of ionic radii and the diffusion constant for silver and its temperature dependence are in good agreement with experiment.
Abstract: A molecular-dynamcis study of silver diffusion in superionic conductor $\ensuremath{\alpha}$-AgI is performed. Interionic potentials are constructed using Pauling's ideas of ionic radii. The diffusion constant for silver and its temperature dependence are in good agreement with experiment. Good agreement is also obtained for the silver density map with the experiment of Cava, Reidinger, and Wuensch.
270 citations
TL;DR: In the case of LiNbO3, the glass conductivities are many orders of magnitude greater than that of the single crystal as mentioned in this paper. But they are not sufficient for rapidly quenched vitreous oxides for applications as solid electrolytes.
Abstract: Alkali niobate and tantalate glasses have been prepared by rapid quenching. These glasses exhibit room‐temperature ionic conductivities as high as 10−5 (Ω cm)−1 and electronic conductivities less than 10−11(Ω cm)−1. In the case of LiNbO3, the glass conductivity is many orders of magnitude greater than that of the single crystal. These conductivities are sufficiently high for rapidly quenched vitreous oxides to be considered for applications as solid electrolytes.
190 citations
126 citations
TL;DR: In this paper, the transcrystalline and inter-crystaline resistances of polycrystallinized Li3N were evaluated at 25°C and the inter-cell conductivity was found to be 6.6×10−4 (ohm cm)−1 and 24.1 kJ/mole, respectively.
114 citations
TL;DR: In this paper, it was found that a large fraction of the total current was transported by the surface counter-ions, their mobility being ⩾10 4 times that of the internal ones.
98 citations
77 citations
TL;DR: In this article, the 1H noise-decoupling field was used to measure the heating effect of aqueous solution of a 50 50 vol% mixture of acetone-d6 and carbon tetrachloride.
74 citations
IBM1
TL;DR: Anomalous behavior has been observed in the ionic conductivity of (Na,K) mixed crystals of the alkali gallates and aluminate of the β-Al2O3 type fast ion conductors as mentioned in this paper.
66 citations
TL;DR: In this article, the structure of molten BaCl2 has been investigated by applying the technique of neutron diffraction to isotopically enriched samples, and three partial factors relating to Ba-Ba, Cl-Cl and Ba-Cl correlations have been successfully extracted from the experimental data.
Abstract: The structure of molten BaCl2 has been investigated by applying the technique of neutron diffraction to isotopically enriched samples. The three partial factors relating to Ba-Ba, Cl-Cl and Ba-Cl correlations have been successfully extracted from the experimental data. It is concluded that the correct description of the melt is in terms of Ba2+ ions and Cl- ions rather than BaCl+ complexes and Cl- ions as was earlier supposed. The observed structure of the liquid is related to the fast ionic conductivity known to characterise the high temperature (cubic) phase of solid BaCl2.
TL;DR: In this article, a technique for the calculation of the thermoelectric power in many-particle systems exhibiting hopping conduction is presented, which provides very useful information about the microscopic nature of the ion hopping process in solid electrolytes.
TL;DR: The ionic conductivity of pure and doped polycrystalline trisodium orthophosphate (Na3PO4) has been measured, using an ac technique, from 150 to 350°C as mentioned in this paper.
TL;DR: In this paper, an excluded volume model was proposed for the cation-anion interaction in superionic conductors and the resulting cationanion correlations were in excellent quantitative agreement with the pair distribution function derived from EXAFS measurements on AgI in both the normal beta and superionic alpha phases.
Abstract: An excluded volume model is proposed for the cation-anion interaction in superionic conductors. The resulting cation-anion correlations are in excellent quantitative agreement with the pair distribution function derived from EXAFS measurements on AgI in both the normal beta and superionic alpha phases. Further, from the EXAFS data alone, the model predicts the substantial increase in ionic conductivity at the phase transition as well as the modest temperature dependence above it.
TL;DR: In this article, the 19F self-diffusion was investigated in PbF2, up to the melting point, by NMR techniques, and the results were compared with those of ionic conductivity and are found to be 0.88+or-0.10 eV, assuming a vacancy mechanism of selfdiffusion is operative.
Abstract: The 19F- self-diffusion has been investigated in PbF2, up to the melting point, by NMR techniques. Relaxation time measurements (T1, T2 and T1 rho ) have been made from 300 to 1095K. Anomalous behaviour above 500K, similar to that reported in previous investigations, is found to be due to paramagnetic impurity produced as a result of the high reactivity of PbF2 at these temperatures. Direct F- diffusion measurements have been made using NMR spin echoes from 570K to 1005K. These results are compared with those of ionic conductivity and are found to be 0.88+or-0.10 eV, assuming a vacancy mechanism of self-diffusion is operative. Above the phase transition at 705K the F- diffusion coefficient changes more slowly with temperature, being characterised by an activation energy of 0.20+or-0.02 eV, which is typical of a fast ion conductor.
TL;DR: In this article, a new material for self-contained all-solid-state electrochromic devices with fast response was proposed, which is called phosphotungstic acid (PWA).
Abstract: We report a new material for self‐contained all‐solid‐state electrochromic devices with fast response. The material is phosphotungstic acid (PWA) which, at room temperature, is both an electrochromic material and an ionic conductor. Response times of 50 msec have been measured in cells of type M/PWA/SnO2, where M denotes an electrode that provides ions of Ag, Cu, or Li. The cell exhibits memory.
TL;DR: Two solid solutions Pb 1−x Th x F 2+2x of fluorite and of tysonite types were prepared in the PbF 2 -ThF 4 system as mentioned in this paper.
TL;DR: The structural results suggest a hydrogen bonding network which favors the high H + ionic conductivity observed in this solid electrolyte material as mentioned in this paper, which suggests a hydrogen bond network is formed by hydrogen uranyl phosphate tetrahydrate, HUO 2 PO 4 ·4H 2 O (HUP).
TL;DR: In this paper, the influence of the defect concentration on the ionic conductivity of solid solutions of high sodium sulfate (Na 2 SO 4 I) is presented.
TL;DR: In this article, the effect of seeding magnesium-doped sodium-beta-alumina with pure β-alUMina has been investigated; the resulting product has been compared with material with the same composition but unseeded.
Abstract: The effect of seeding magnesium-doped sodium-beta-alumina with pureβ″-alumina has been investigated; the resulting product has been compared with material with the same composition but unseeded. The manner in which this technique controls the microstructure and phase composition has been studied and related to the measured ionic conductivity.
TL;DR: Anisotropic dielectric behavior of the superionic conductor lithium nitride (Li3N) is reported for low temperature where the dc ionic conductivity can be neglected (T < 17oK) as discussed by the authors.
TL;DR: In this paper, the effect of cobalt as a dopant for sodium-beta-alumina has been studied in polycrystalline materials prepared from a mixed oxide precursor.
Abstract: The effect of cobalt as a dopant for sodium-beta-alumina has been studied in polycrystalline materials prepared from a mixed oxide precursor. Two materials have been examined; one containing a small amount of cobalt as well as magnesium as a dopant and the other magnesium alone to produce the same molar quality of divalent dopant. The sintering behaviour, microstructure and phase composition are shown to be related to the measured ionic conductivity.
TL;DR: Ionic conductivity measurements have been made on pure, copperdoped and cadmium-doped single crystals as mentioned in this paper, and it has been shown that copper exists as Cu + in these crystals.
TL;DR: The ionic conductivity of two dimensional alkali metal intercalation compounds depends on factors such as the ratio between the number of intercalated ions and available vacancies in the v.w.d. gap as discussed by the authors.
TL;DR: In this paper, the mechanism of ionic conduction is studied in both types of oxide and it is found that it is dependent on the physical structure of the oxide, which determines the field distribution.
TL;DR: In this article, the ionic thermoelectric power of a superionic conductor is calculated using a lattice gas model in one dimension for the case where the lattice sites are 50% occupied.
Abstract: The ionic thermoelectric power of a superionic conductor is calculated using a lattice gas model in one dimension for the case where the lattice sites are 50% occupied. The calculated thermoelectric power is inversely proportional to the absolute temperature and the activation energy for ionic conduction is equal to the heat of transport. The results explain experiments fairly good.
TL;DR: A completely automated asymmetric interferometer, useful for temperature dependent (4.2-500 K) complex reflection measurements in the far-infrared region, is outlined in this paper.