Abstract
Using non-isothermal thermogravimetry (TG), the oxidation kinetics of oxygen-deficient lithium-titanium ferrospinel, Li0.649Fe 1.598Ti0.5Zn0.2Mn0.051O 4-δ, manufactured by ceramic engineering is investigated. The oxidation annealing of powder samples is performed in air. According to the X-ray phase analysis, the processes giving rise to variations in oxygen content occur within single-phase spinel structure. The experimental kinetic results are processed using the Netzsch Thermokinetics software. The oxidation rate constants and the effective coefficients of atmospheric oxygen diffusion into the ferrites are determined. The effective activation energy E of oxygen diffusion is found to be 1.95 eV. It is demonstrated that an increase in the oxygen non-stoichiometry parameter δ as a result of recovery annealing of ferrite powders in vacuum at T = 1,070 K for 2 h gives rise to a slight decrease in E down to 1.89 eV. The activation energy of oxygen grain-boundary diffusion is identified by the electroconduction method. The resulting value 1.93 eV is fairly consistent with that obtained by TG.
| Original language | English |
|---|---|
| Pages (from-to) | 883-887 |
| Number of pages | 5 |
| Journal | Journal of Thermal Analysis and Calorimetry |
| Volume | 102 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - Dec 2010 |
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Keywords
- Kinetics
- Oxidation of lithium-titanium ferrites
- Oxygen diffusion
- TG
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
Cite this
Investigation of oxidation processes in non-stoichiometric lithium-titanium ferrites using TG analysis. / Surzhikov, Anatoly Petrovich; Frangulyan, T. S.; Ghyngazov, S. A.; Lysenko, E. N.
In: Journal of Thermal Analysis and Calorimetry, Vol. 102, No. 3, 12.2010, p. 883-887.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Investigation of oxidation processes in non-stoichiometric lithium-titanium ferrites using TG analysis
AU - Surzhikov, Anatoly Petrovich
AU - Frangulyan, T. S.
AU - Ghyngazov, S. A.
AU - Lysenko, E. N.
PY - 2010/12
Y1 - 2010/12
N2 - Using non-isothermal thermogravimetry (TG), the oxidation kinetics of oxygen-deficient lithium-titanium ferrospinel, Li0.649Fe 1.598Ti0.5Zn0.2Mn0.051O 4-δ, manufactured by ceramic engineering is investigated. The oxidation annealing of powder samples is performed in air. According to the X-ray phase analysis, the processes giving rise to variations in oxygen content occur within single-phase spinel structure. The experimental kinetic results are processed using the Netzsch Thermokinetics software. The oxidation rate constants and the effective coefficients of atmospheric oxygen diffusion into the ferrites are determined. The effective activation energy E of oxygen diffusion is found to be 1.95 eV. It is demonstrated that an increase in the oxygen non-stoichiometry parameter δ as a result of recovery annealing of ferrite powders in vacuum at T = 1,070 K for 2 h gives rise to a slight decrease in E down to 1.89 eV. The activation energy of oxygen grain-boundary diffusion is identified by the electroconduction method. The resulting value 1.93 eV is fairly consistent with that obtained by TG.
AB - Using non-isothermal thermogravimetry (TG), the oxidation kinetics of oxygen-deficient lithium-titanium ferrospinel, Li0.649Fe 1.598Ti0.5Zn0.2Mn0.051O 4-δ, manufactured by ceramic engineering is investigated. The oxidation annealing of powder samples is performed in air. According to the X-ray phase analysis, the processes giving rise to variations in oxygen content occur within single-phase spinel structure. The experimental kinetic results are processed using the Netzsch Thermokinetics software. The oxidation rate constants and the effective coefficients of atmospheric oxygen diffusion into the ferrites are determined. The effective activation energy E of oxygen diffusion is found to be 1.95 eV. It is demonstrated that an increase in the oxygen non-stoichiometry parameter δ as a result of recovery annealing of ferrite powders in vacuum at T = 1,070 K for 2 h gives rise to a slight decrease in E down to 1.89 eV. The activation energy of oxygen grain-boundary diffusion is identified by the electroconduction method. The resulting value 1.93 eV is fairly consistent with that obtained by TG.
KW - Kinetics
KW - Oxidation of lithium-titanium ferrites
KW - Oxygen diffusion
KW - TG
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UR - http://www.scopus.com/inward/citedby.url?scp=78650725896&partnerID=8YFLogxK
U2 - 10.1007/s10973-010-0912-8
DO - 10.1007/s10973-010-0912-8
M3 - Article
VL - 102
SP - 883
EP - 887
JO - Journal of Thermal Analysis and Calorimetry
JF - Journal of Thermal Analysis and Calorimetry
SN - 1388-6150
IS - 3
ER -