Mossbauer effect studies on the formation of iron oxide phases synthesized via microwave-hydrothermal route

• Type: Article in International Scientific Journal
• Date: 2006

Authors

Bakare, PP (Author) Other; Date, SK (Author) Other; Khollam, YB (Author) Other; Deshpande, SB (Author) Other; Potdar, HS (Author) Other; Salunke Gawali, S (Author) Other; Varret, F (Author) Other; Pereira, E (Author) FCUP

Journal

Title: Hyperfine Interactions

Vol. 168

Pages: 1127-1132

ISSN: 0304-3843

Publisher: Springer Nature

Indexing

ISI Web of Knowledge - 10 Citations

Scopus - 10 Citations

Scientific classification

FOS: Natural sciences > Physical sciences

Other information

Authenticus ID: P-004-NEH

DOI: 10.1007/s10751-006-9458-3

Abstract (EN): Microwave-hydrothermal (MH) route was employed to synthesize various iron oxide phases in ultra-fine crystalline powders by using ferrous sulphate and sodium hydroxide as starting chemicals. All chemical reactions were carried out under identical MH conditions, namely, at 190 degrees C, 154 psi, 30 min, by varying the molar ratio (MR) of FeSO4/NaOH in the aqueous solutions. The variation of MR has a dramatic effect on the crystallization behavior of various phases of iron oxides under MH processing conditions. For example, spherical agglomerates of Fe3O4 powder were obtained if MR equal to 0.133 (pH > 10 sample A). On the other hand non-stoichiometric Fe3O4 powders (Sample B) were obtained for all higher MR of FeSO4/NaOH between 0.133 and 4.00 (6.6 < H < 10). However, when MR was equal to 4.0 (pH congruent to 6.6) a varied distribution of shapes and sizes of agglomerates of -Fe2O3 powders (sample C) were produced. Fe-57 Mossbauer spectra were recorded for all the three sets of samples at room temperature. In the case of sample B, temperature dependent Mossbauer spectra were recorded in the range of 77-300 K to understand the non-stoichiometric nature of Fe3O4 powders. All these results are discussed in the present paper.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 6