Magnetic properties of nanocrystalline FeNiCo x ZrB alloys ( x =0, 10, 20)

Magnetic properties of amorphous and nanocrystalline Fe31Ni50Zr7B12, Fe31Ni40Co10Zr7B12 and Fe31Ni30Co20Zr7B12 alloys were studied by an unconventional “rf-Mossbauer” technique. Introduction of Co atoms into FeNiZrB alloy leads to a large increase of anisotropy field that suppresses the rf collapse effect. The rf induced crystallization effect observed in Co-containing alloys was attributed to the rf sidebands effect which induced in the alloys mechanical deformations via the magnetostriction. This effect is particularly strong in amorphous alloys and in nanocrystalline alloys containing significant fraction of amorphous matrix and is absent in Co-free alloy.