Activation energy and conductivity relaxation of sodium tellurite glasses

1999 ◽  
Vol 59 (2) ◽  
pp. 899-904 ◽  
Author(s):  
A. Pan ◽  
A. Ghosh
Keyword(s):  
Activation Energy ◽  
Tellurite Glasses ◽  
Conductivity Relaxation ◽  
Sodium Tellurite

Vibrational modes of sodium–tellurite glasses: Local structure and Boson peak changes

2007 ◽  
Vol 68 (5-6) ◽  
pp. 1035-1039 ◽  
Author(s):  
A.G. Kalampounias ◽  
S.N. Yannopoulos ◽  
G.N. Papatheodorou
Keyword(s):  
Local Structure ◽  
Boson Peak ◽  
Tellurite Glasses ◽  
Vibrational Modes ◽  
Sodium Tellurite

ChemInform Abstract: Structure of Sodium Tellurite Glasses: Sodium Cation Environments from Sodium-23 NMR.

ChemInform ◽  
2010 ◽  
Vol 26 (31) ◽  
pp. no-no
Author(s):  
S. L. TAGG ◽  
R. E. YOUNGMAN ◽  
J. W. ZWANZIGER
Keyword(s):  
Sodium Cation ◽  
Tellurite Glasses ◽  
Sodium Tellurite ◽  
Abstract Structure

scholarly journals Immittance Studies of Bi6Fe2Ti3O18 Ceramics

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5286 ◽  
Author(s):  
Agata Lisińska-Czekaj ◽  
Dionizy Czekaj ◽  
Barbara Garbarz-Glos ◽  
Wojciech Bąk
Keyword(s):  
Activation Energy ◽  
Electric Modulus ◽  
Complex Impedance ◽  
Dc Conductivity ◽  
Modulus Function ◽  
Conductivity Relaxation ◽  
Frequency Range ◽  
A Value ◽  
Polycrystalline Ceramics ◽  
Electric Behavior

Results of studies focusing on the electric behavior of Bi6Fe2Ti3O18 (BFTO) ceramics are reported. BFTO ceramics were fabricated by solid state reaction methods. The simple oxides Bi2O3, TiO2, and Fe2O3 were used as starting materials. Immittance spectroscopy was chosen as a method to characterize electric and dielectric properties of polycrystalline ceramics. The experimental data were measured in the frequency range Δν = (10−1–107) Hz and the temperature range ΔT = (−120–200) °C. Analysis of immittance data was performed in terms of complex impedance, electric modulus function, and conductivity. The activation energy corresponding to a non-Debye type of relaxation was found to be EA = 0.573 eV, whereas the activation energy of conductivity relaxation frequency was found to be EA = 0.570 eV. An assumption of a hopping conductivity mechanism for BFTO ceramics was studied by ‘universal’ Jonscher’s law. A value of the exponents was found to be within the “Jonscher’s range” (0.54 ≤ n ≤ 0.72). The dc-conductivity was extracted from the measurements. Activation energy for dc-conductivity was calculated to be EDC = 0.78 eV, whereas the dc hopping activation energy was found to be EH = 0.63 eV. The obtained results were discussed in terms of the jump relaxation model.

Intermediate Range Order in Sodium Tellurite Glasses

1996 ◽  
Vol 455 ◽  
Author(s):  
J. W. Zwanziger ◽  
J. C. McLaughlin ◽  
S. L. Tagg
Keyword(s):  
Random Model ◽  
Range Order ◽  
Sodium Oxide ◽  
Oxide Content ◽  
Tellurite Glasses ◽  
Sodium Ions ◽  
Distance Distributions ◽  
Sodium Tellurite ◽  
Maximum Stability ◽  
Spin Echoes

ABSTRACTInformation about the spatial distribution of sodium cations in sodium tellurite glasses is obtained from the decay rate of sodium spin echoes. The spin echoes decay due to the magnetic dipole coupling between sodium nuclei, with each pair contributing to the rate in proportion to 1/r6, where r is the distance between the pair. The experiment is used to probe the sodium distributions in sodium tellurite glasses as a function of sodium oxide content, and the resulting distance distributions are interpreted by comparison with model distributions. At low sodium contents the distribution is similar to that of a random model in which the sodium ions are constrained to be no closer than a minimum cut-off distance. At higher contents the distributions deviate significantly from the random model, suggesting the onset of medium range order in the distribution of sodium ions. This order is most pronounced at 20% sodium oxide content, the composition at which this glass has been claimed to have maximum stability against devitrification.

Glass transformation temperature and stability of tellurite glasses

2003 ◽  
Vol 18 (2) ◽  
pp. 402-406 ◽  
Author(s):  
Raouf El-Mallawany
Keyword(s):  
Activation Energy ◽  
Differential Scanning Calorimetry ◽  
Transformation Temperature ◽  
Unit Volume ◽  
Tellurite Glasses ◽  
Heating Rates ◽  
Scanning Calorimetry ◽  
Glass Transformation ◽  
Glass Series ◽  
Calculated Number

The glass transformation (Tg) and onset crystallization temperatures (Tx) of (100 – x) TeO2–(x)V2O5, (x = 10, 35, and 50 mol%) glasses were measured in the temperature range 300–800 K by differential scanning calorimetry at different heating rates. From the variation of the heating rate, the glass transition activation energy was calculated by different methods. The glass stabilization range S = Tx – Tg was calculated for the whole glass series. Quantitative analysis of the glass transformation temperature was carried out using the calculated number of bonds per unit volume and oxygen packing density.

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