Influence of Gd on the structure and magnetic properties of FINEMET

A set of Fe73.5GdxNb3Cu1Si13.5B9 samples with Gd concentration x = 0 - 3 at % and the Fe71.5Gd5Cu1Si13.5B9 alloy have been investigated: (i) concerning their ability to form nanocrystalline material after heat treatment and (i i) with respect to the Gd influence on the magnetic properties. All the sam ples showed a nanocrystalline structure after appropriate heat treatment, e xcept the one with 5 at% of Gd. The observed decrease of the saturation mag netization with increasing Gd content indicates the ferrimagnetic exchange coupling between the Gd and Fe atoms. The Curie temperature was found to be increasing with Gd content up to 3 at% of Gd.