Structure, thermal and electrical properties of Fe-B-Co-Nb-Ni-Si high-entropy metallic glass

Abstract

New nanostructured Fe₂₅B_17.5Co_21.35Nb_3.65Ni₂₅Si_7.5 high-entropy metallic glass is synthesized by dint of splat-quenching technique. The estimated cooling rate is ~106 K/s. The coherently scattering domain size (crystallite size) of films of Fe₂₅B_17.5Co_21.35Nb_3.65 Ni₂₅Si_7.5 high-entropy metallic glass estimated by the Sherer formula is ~ 3 nm. The high-entropy metallic glass shows a high temperature of glass transition Tg ~ 800 K and the initial temperature of crystallization Tx ~ 863 K. After annealing to ~ 1010 K (above the crystallization temperature) and subsequent slow cooling, the amorphous films crystallize with the formation of several crystalline phases. The temperature dependencies of electrical resistivity of the Fe₂₅B_17.5Co_21.35Nb_3.65Ni₂₅Si_7.5 films indicate the occurrence of phase transformations. The phase transformation temperature (temperature of crystallization) is ~ 869 K. This value agrees well with the value obtained from the differential thermal analysis.