Study of metal-ferrite composites: complementary use of ⁵⁷Fe Mössbauer spectrometry, X-ray diffraction and TG analysis

¹ Institut de Physique et Chimie des Matériaux de Strasbourg, Groupe des Matériaux Inorganiques (UMR 7504), 23 rue du Loess, 67037 Strasbourg Cedex, France
² Laboratoire de Physique de l'État Condensé (UMR 6087), Université du Maine, avenue O. Messiaen, BP 535, 72085 Le Mans Cedex 9, France

Corresponding author: viart@ipcms.u-strasbg.fr

Received: 2 July 2001
Revised: 21 November 2001
Accepted: 7 January 2002
Published online: 15 April 2002

Abstract

The complementarity between ⁵⁷Fe Mössbauer spectrometry and classical methods of powder characterizations is pointed out for determining the formula of metal-ferrite composites (FeCo)_a(Co_xFe O₄). It is shown that X-ray diffraction is essential to determine the composition of the metal, while TG measurements in air give an approximate value for the metal ratio. In-field spectrometry is expected as the most suitable tool to determine the Fe sites occupancy, although the complex hyperfine structure might originate some misfits. The composites formulae were therefore determined by selecting the set of refined Mössbauer parameters that were in best agreement with the TG measurements. Magnetic measurements prove the validity of such an approach.