SURFACE PROPERTIES OF A NANOCRYSTALLINE Fe-Ni-Nb-B ALLOY AFTER NEUTRON IRRADIATION

Milan Pavúk – Jozef Sitek – Katarína Sedlačková

   The effect of neutron radiation on the surface properties of the nanocrystalline (Fe_0.25Ni_0.75)₈₁Nb₇B₁₂ alloy was studied. Firstly, amorphous (Fe_0.25Ni_0.75)₈₁Nb_{_7}B₁₂ ribbon was brought by controlled annealing to the nanocrystalline state. After annealing, the samples of the nanocrystalline ribbon were irradiated in a nuclear reactor with neutron fluences of 1×10¹⁶ cm^{-2,/sup> and 1×1017 cm-2. By utilizing the magnetic force microscopy (MFM), topography and a magnetic domain structure were recorded at the surface of the ribbon-shaped samples before and after irradiation with neutrons. The results indicate that in terms of surface the nanocrystalline (Fe_0.25Ni_0.75)₈₁Nb₇B₁₂ alloy is radiation-resistant up to a neutron fluence of 1×1017 cm-2. The changes in topography observed for both irradiated samples are discussed.}

Keywords: nanocrystalline materials, neutron radiation effects, magnetic force microscopy, MFM, surface topography

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