Local structure of Ni80X20 (X: Cr, Mn, Pd) solid-solution alloys and its response to ion irradiation

The local structure of Ni80X20 (X: Cr, Mn, Pd) solid-solution alloys was investigated with x-ray absorption and total scattering x-ray diffraction methods. Atomic pair distribution function (PDF) analysis indicated that the local lattice distortion is strongly relevant to the atomic size mismatch, and the local lattice distortion in Ni80Pd20 alloy is obviously larger than that in other solid-solution alloys. The bond length of different atomic pairs was derived from the fitting of extended x-ray absorption fine structure spectra. Quantitative analysis of the local bonding environment in Ni80Cr20 during Ni ion irradiation suggested that Cr atoms tend to form clusters in Ni80Cr20 with the increase of ion dose.