Change of electronic properties on transition from high-entropy to Ni-rich (TiZrNbCu)1−xNi alloys

Abstract

We present results of comprehensive study of electronic properties of (TiZrNbCu) 1−x Ni x metallic glasses performed in broad composition range x encompassing both, high entropy (HE) range, and conventional Ni-base alloy concentration range, x ≥ 0.35. The electronic structure studied by photoemission spectroscopy and low temperature specific heat (LTSH) reveal a split-band structure of density of states inside valence band with d-electrons of Ti, Zr, Nb and also Ni present at Fermi level N (E F ), whereas LTSH and magnetoresistivity results show that variation of N (E F ) with x changes in Ni-base regime. The variation of superconducting transition temperatures with x closely follows that of N (E F ). The electrical resistivities of all alloys are high and decreasewith increasing temperature over most of explored temperature range, and their temperature dependence seems dominated by weak localization effects over a broad temperature range (10 − 300 K). The preliminary study of Hall

Transition from High-Entropy to Conventional Alloys: Which Are Better?

“…Further, some intriguing phenomena including the Kondo effect [ 20 ], quantum critical behavior [ 21 ] and the boson peak [ 22 ] have been observed. Moreover, several important problems in contemporary physics including the localization of electrons and phonons, various percolation phenomena at different crystal lattices, metal–insulator transitions and the nature of the boson peak in disordered systems can be studied effectively using HEAs [ 22 , 23 , 24 , 25 , 26 ].…”

“…The research of the other five groups of similar elements known to form HEAs [ 13 ] has, thus far, been rather limited [ 6 , 14 , 15 ]. Therefore, the distribution of research on HEAs has been quite uneven, both as regards topics and alloy families [ 6 , 13 , 14 , 15 ], which affects the progress in this field [ 22 , 23 , 24 , 25 , 26 ]. The lists of some topics and HEA/CCA systems which deserve more intense study can be found in recent reviews of the literature [ 5 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] and our recent reports [ 22 , 23 , 24 , 25 , 26 ].…”

“…Therefore, the distribution of research on HEAs has been quite uneven, both as regards topics and alloy families [ 6 , 13 , 14 , 15 ], which affects the progress in this field [ 22 , 23 , 24 , 25 , 26 ]. The lists of some topics and HEA/CCA systems which deserve more intense study can be found in recent reviews of the literature [ 5 , 9 , 10 , 11 , 12 , 13 , 14 , 15 , 16 , 17 ] and our recent reports [ 22 , 23 , 24 , 25 , 26 ]. As regards new CCAs, “nonlinear alloys” built from unexpected combinations of elements (such as combinations of 3d transition metals with refractory ones [ 1 , 2 , 22 , 23 , 24 , 25 , 26 ]) have been proposed [ 6 ].…”

“…The research of their physical properties is still insufficient, despite their potential as functional materials [ 5 , 28 ], and the conceptual importance of these properties [ 20 , 21 , 22 , 23 , 24 , 25 , 26 , 29 ]. The main problem in the selection of HEA/CCA systems possessing desirable properties is the limited conceptual understanding of these complex multicomponent systems.…”

“…The main problem in the selection of HEA/CCA systems possessing desirable properties is the limited conceptual understanding of these complex multicomponent systems. The main hindrance for such an understanding of both crystalline (c-) and amorphous (a-) HEAs and CCAs is probably the lack of detailed insight into their electronic structures (ESs), which, in metallic systems, determine all intrinsic properties [ 5 , 15 , 17 , 18 , 19 , 20 , 21 , 22 , 23 , 24 , 25 , 26 , 30 , 31 , 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ] including the mechanical ones [ 5 , 15 , 18 , 19 , 31 ]. Fortunately, the number of theoretical studies of ESs and selected properties of CCAs has increased dramatically over the last ten years and, at present, largely exceeds the number of experimental studies of their ES.…”