DIFFUSION, SEGREGATION AND DESORPTION OF POTASSIUM FROM K2Fe22O34 FERRITE
- 1 June 2011
- journal article
- research article
- Published by World Scientific Pub Co Pte Ltd in Functional Materials Letters
- Vol. 04 (02) , 179-182
Abstract
The samples of K 2 Fe 22 O 34 phase were synthesized and characterized by XRD, BET, SEM-EDX and XPS. K+ diffusion was investigated by impedance spectroscopy, whereas the surface segregation and desorption were monitored by Kelvin Probe (changes in work function) and Species Resolved Thermal Alkali Desorption, at the temperature range of 600–1000 K. The analysis of changes in work function and desorption signals ( K and K+ ) at various temperatures allowed to resolve the kinetic parameters (flux, rate constants, activation energies) of potassium diffusion, surface accumulation and desorption. Based on the obtained results, the simple, functional model of bulk and surface changes of K -β-ferrite was proposed.Keywords
This publication has 18 references indexed in Scilit:
- Potassium stabilization in β-K2Fe22O34 by Cr and Ce doping studied by field reversal methodSolid State Ionics, 2011
- Irreversible deactivation of styrene catalyst due to potassium loss—Development of antidote via mechanism pinningCatalysis Today, 2010
- Thermodynamics of solid electrolytes and related oxide ceramics based on the fluorite structureJournal of Materials Chemistry, 2010
- Advanced materials for sodium-beta alumina batteries: Status, challenges and perspectivesJournal of Power Sources, 2010
- Energy-pooling transitions to doubly excited K atoms at a promoted iron-oxide catalyst surface: more than 30 eV available for reactionPhysical Chemistry Chemical Physics, 2009
- A new improvement of catalysis by solid-state electrochemistry: An electrochemically assisted NOx storage/reduction catalystJournal of Catalysis, 2008
- Reverse effect of doping on stability of principal components of styrene catalyst: KFeO2 and K2Fe22O34Journal of Catalysis, 2007
- Quenching of potassium loss from styrene catalyst: Effect of Cr doping on stabilization of the K2Fe22O34 active phaseJournal of Catalysis, 2006
- Energetics of Potassium Loss from Styrene Catalyst Model Components: Reassignment of K Storage and Release PhasesJournal of Catalysis, 2002
- Stimulated Raman Spectroscopy of a K-Promoted Catalyst Surface: Spectroscopic Evidence of K* Rydberg State FormationLangmuir, 2000