Naslov
Electronic structure and properties of (TiZrNbCu)_1-xNi_x high entropy amorphous alloys

Autori
Biljaković, Katica ; Remenyi, György ; Figueroa, Ignacio ; Ristić, Ramir ; Pajić, Damir ; Kuršumović, Ahmed ; Starešinić, Damir ; Zadro, Krešo ; Babić, Emil

Izvornik
Journal of alloys and compounds (0925-8388) 695 (2017); 2661-2668

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
Metallic glasses ; Electronic band structure ; Heat capacity ; Mechanical properties

Sažetak
A comprehensive study of selected properties of four (TiZrNbCu)_1-xNi_x (x ≤ 0.25) amorphous high entropy alloys (a-HEA) has been performed. The samples were ribbons about 20 µm thick and their fully amorphous state was verified by X- ray diffraction and thermal analysis. The surface morphology, precise composition and the distribution of components were studied with a Scanning electron microscope (SEM) with an energy dispersive spectroscopy (EDS) attachment. The properties selected were the melting temperature (T_m), the low temperature specific heat (LTSH), the magnetic susceptibility χexp and the Young´s modulus (E). Whereas LTSH and χexp were measured for the as-cast samples, E was measured both for as-cast samples and relaxed samples (after a short anneal close to the glass transition temperature). The LTSH showed that the electronic density of states at the Fermi level, N_0(E_F), decreases with increasing x, whereas the Debye temperature (θ_D) increases with x. This is similar to what is observed in binary and ternary amorphous alloys of early transition metals (TE) with late transition metals (TL) and indicates that N0(EF) is dominated by the d-electrons of the TE. The LTSH also showed the absence of superconductivity down to 1.8K and indicated the emergence of the Boson peak above 4K in all alloys.The free-electron like paramagnetic contribution to χexp also decreases with x, whereas E, like θ_D, increases with x, indicating enhanced interatomic bonding on addition of Ni. The applicability of the rule of mixtures to these and other similar HEAs is briefly discussed.

Izvorni jezik
Engleski

Znanstvena područja
Fizika

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