Defect structure of Co3O4cobalt oxide

Defect structure of Co3O4cobalt oxide

Zbigniew Grzesik Anna Kaczmarska 

Department of Physical Chemistry and Modelling, Faculty of Materials Science and Ceramics, AGH University of Science and Technology, al. A. Mickiewicza, Krakow, 30-059, Poland

Page: 
103-109
|
DOI: 
https://doi.org/10.3166/acsm.40.103-109
Received: 
1 October 2015
|
Accepted: 
7 January 2016
|
Published: 
11 May 2016
| Citation

OPEN ACCESS

Abstract: 

The deviation from stoichiometry, y, in the Co3O4 oxide has been studied as a function of temperature (973-1173 K) and oxygen pressure (30-105 Pa) using microthermogravimetric technique. It has been found that at low oxygen pressures, the deviation from stoichiometry decreases with increasing oxygen pressure, reaching zero value in intermediate oxygen pressure range and for higher pressures it starts to increase. This behaviour strongly suggests the presence of complex defect structure in the studied oxide. At very low oxygen pressures, close to the dissociation pressure of the oxide, interstitial cations are the predominant ionic defects, while at high pressures cation vacancies predominate. Using the obtained results of nonstoichiometry, the concentrations of predominant point defects in the studied oxide have been calculated as a function of temperature and oxygen pressure. 

1. Introduction
2. MATERIALS AND EXPERIMENTAL PROCEDURE
3. Results and Discussion
4. SUMMARY
Acknowledgments

This work was supported by the statutory research of Faculty of Materials Science and Ceramics, AGH (no. 11.11 .160 .257 ).

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