Formation and cation distribution in supported manganese ferrite nanoparticles: an X-ray absorption study

Carta, Daniela, Casula, MF and Mountjoy, G (2008) Formation and cation distribution in supported manganese ferrite nanoparticles: an X-ray absorption study Physical Chemistry Chemical Physics, 10. pp. 3108-3117.

Full text not available from this repository.

Abstract

Extended X-ray absorption fine structure (EXAFS) and X-ray absorption near-edge structure (XANES) techniques at both Fe and Mn K-edges were used to investigate the formation of MnFe2O4 nanoparticles embedded in a silica aerogel matrix as a function of calcination temperature (at 450, 750 and 900 1C). Up to 450 1C, two separated highly-disordered phases of iron and manganese are present. With increasing the temperature (to 750 and 900 1C), the structure of aerogel nanoparticles becomes progressively similar to that of the spinel structure MnFe2O4 (jacobsite). Quantitative determination of cations distribution in the spinel structure shows that aerogels calcined at 750 and 900 1C have a degree of inversion i = 0.20. A pure jacobsite sample synthesised by co-precipitation and used as a reference compound shows a much higher degree of inversion (i = 0.70). The different distribution of iron and manganese cations in the octahedral and tetrahedral sites in pure jacobsite and in the aerogels can be ascribed to partial oxidation of Mn2+ to Mn3+ in pure jacobsite, confirmed by XANES analysis, probably due to the synthesis conditions.

Item Type:	Article
Divisions :	Faculty of Engineering and Physical Sciences > Chemistry
Authors :	Name Email ORCID Carta, Daniela d.carta@surrey.ac.uk Casula, MF Mountjoy, G
Date :	2008
DOI :	10.1039/B800359A
Depositing User :	Jane Hindle
Date Deposited :	01 Sep 2017 12:34
Last Modified :	16 Jan 2019 18:56
URI:	http://epubs.surrey.ac.uk/id/eprint/842129

Actions (login required)

View Item

Downloads