HIGH-PRESSURE STUDIES ON INVAR-ALLOYS - A KEY FOR UNDERSTANDING ITINERANT ELECTRON MAGNETISM

One of the favourable approaches to understand itinerant electron magn etism in 3d transition metals and their alloys is the study of the pre ssure effect on their magnetic properties. In this respect, the fcc Fe -based Invar alloys are the best candidates for such studies due to th eir known strong mutual relationship between magnetism and volume. In this paper we demonstrate how high-pressure Fe-57 Mossbauer studies on selected Fe-based Invar alloys provide new findings on the stability of the magnetic moments and their interactions in these systems. The e xperimental results are in a good agreement with recent spin-polarized band calculations of the volume dependence of the Fe magnetic moment in ordered Fe3Ni and Fe3Pt. It is shown that such high pressure studie s not only shed light on the origin of the Invar anomalies in those al loys but also provide the basis for a better understanding of itineran t 3d magnetism.