Structure Analysis of Sputtered CoSb and CoSb + InSb Films Subjected to Swift Heavy Ion Irradiation

Cobalt triantimonide (CoSb₃) is highly relevant in thermoelectric materials research due to its cage like skutterudite crystal structure. Although its performance is limited by a relatively high thermal conductivity, modifying the material through composition adjustments and nanostructuring may address this limitation [1]. This work investigates the mix of CoSb with Indium antimonide (InSb), which also has good thermoelectric properties but form a nanofoam structure when irradiated with high energy heavy ions [2].

Films of CoSb and CoSb + InSb were deposited via magnetron sputtering and then annealed at 473 K and 673 K for 1 h under a vacuum of 10^-6 mBar. The samples annealed at 673 K were irradiated with 8 MeV Au ions with a fluence of 1 × 10¹⁴ cm^-2 . With grazing incidence x-ray diffraction, we certified that zincblende InSb and CoSb₃ phases are present. Rutherford backscattering spectrometry analysis revealed that the films are made of one layer, containing Co, Sb, In and O. It also showed signs that InSb became porous in the irradiated samples.