DOI: 10.1051/jp1:1992126
J. Phys. I France 2 (1992) 101-109

High field magnetization of two types of shortly correlated systems : random anisotroy systems and nanoparticles

B. Barabara¹, J. Filippi¹, A. Marchand¹, P. Mollard¹, V.S. Amaral², X. Devaux³ and A. Rousset<sup>3

1</sup>  Laboratoire de Magnétisme Louis Néel, CNRS, 38042 Grenoble Cedex, France
²  Centro de Fisica, Universidade do Porto INIC, 4000 Porto, Portugal
³  Laboratoire de Chimie des matériaux inorganiques URA-CNRS 1311, Univ. Paul Sabatier, 31062 Toulouse Cedex, France

(Received 15 May 1991, accepted in final form 18 September 1991)

Abstract
The magnetization curves of two types of systems (random anisotropy amorphous alloys and ferromagnetic nanoparticles) having finite correlation lengths have been measured and analysed in a wide range of magnetic fields. The results show how these measurements allow us to determine i) the ferromagnetic (thermal) and the atomic (quenched) correlations in amorphous alloys and ii) the quenched distribution of nanoparticles and their mean magnetic moments (role of chemical disorder at the interface boundaries with the matrix). A general discussion involving both types of systems will conclude this paper.

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