Time-resolved local atomic fluctuations in Fe-based bulk metallic glasses with Invar effect

Invar effect, characteristic to Fe65Ni35 ordered fcc solid solution, was observed also in the case of ferromagnetic bulk metallic glasses (BMGs). While its origin is still a matter of debate, existing explanations for crystalline materials are built on the fcc lattice. However, this approach cannot be used to describe the Invar effect observed in BMGs, because they lack the crystalline structure. The proposed experiment should shed light on what is the real origin of the effect in the BMGs, by in-situ analysis of the local atomic changes, in particular around the atoms that bear a magnetic moment. The samples will be thermally cycled in the beam, going through Curie point both upon heating and upon cooling.