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Exchange bias and spin valve structures with Fe as ferromagnetic layers selectively enriched in 57Fe and Ir–Mn of different compositions as antiferromagnetic pinning layers have been prepared by r.f. sputtering. Conversion Electron Mössbauer Spectroscopy and Magneto Optic Kerr Effect have shown that the local structure and interactions in the whole ferromagnetic layers, with direct influence on their magnetic reversal processes, depend on growing order of the layers and composition of the AF layer. Interfacial atomic diffusion is the main reason of perturbing the local structure of the ferromagnet. Mössbauer Spectroscopy is a powerfool tool which allows a detailed analysis of local configurations, in order to optimize the magnetic and giant magnetoresistive parameters of such multilayers of important technological applications. [ABSTRACT FROM AUTHOR]

Soft magnetic nanocrystalline alloys have attracted great fundamental interest in recent years due to their two-phase structural and magnetic behaviour. We review first the reliability of the fitting procedures of spectra obtained by 57Fe Mössbauer spectrometry which is a very efficient tool to investigate such materials. Then, we report the common features which characterise the temperature dependence of Mössbauer spectra; the hyperfine field temperature dependence of both the crystalline grains and the intergranular phase is discussed for different crystalline fractions in order to model the magnetic behaviour of the nanocrystalline alloys. [ABSTRACT FROM AUTHOR]