Electronic transport and phonon properties of maximally disordered alloys: From binaries to high-entropy alloys
- PDF / 1,318,758 Bytes
- 24 Pages / 584.957 x 782.986 pts Page_size
- 88 Downloads / 220 Views
REVIEW This section of Journal of Materials Research is reserved for papers that are reviews of literature in a given area.
Electronic transport and phonon properties of maximally disordered alloys: From binaries to high-entropy alloys Sai Mu,a) Zongrui Pei, Xianglin Liu, and George M. Stocksb) Materials Science & Technology Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831, USA (Received 14 April 2018; accepted 25 July 2018)
Recent discoveries of multicomponent concentrated solid-solution alloys hold promise for enhanced properties—such as enhanced mechanical properties, radiation tolerance, high temperature strength, corrosion resistance and some novel functional properties, provide a new strategy for alloy design using extreme disorder. Yet, deep understanding of these intriguing properties is complicated by the very effects of disorder that make them interesting. All the desirable properties of these alloys ultimately originate from the disorder-induced properties of underlying electronic structure, lattice dynamics, and thermodynamics. Therefore, understanding the disorder-induced fundamental physical properties is prerequisite for the science-based design of this class of alloys for practical applications. Here, we elucidate the role of extreme (maximal) substitutional disorder plays in the fundamental physics of disordered alloys and review the recently developed theoretical methodologies in modeling the basic physical properties, particularly electronic structure, magnetism, electrical transport, and lattice vibrations in multicomponent concentrated solid-solution alloys.
I. INTRODUCTION
Alloys have played an important role in the history of human civilization, as manifested by the naming of the Bronze and Iron Ages. Today, essentially all of our major technologies are underpinned by metallic alloys that have much in common with their ancient progenitors—they are (typically) based on a single dominant element with dilute additions of other elements and often rely on manipulation of microstructural features for their enhanced properties. It was not until the relatively recent discoveries by Yeh1 and Cantor2 of the first high-entropy alloys (HEAs)3–5— CuCoNiCrAlFe and NiFeCoCrMn—that attention has turned to a different regime—that of multicomponent concentrated solid solution alloys (CSAs)—as providing a new basis for the development of a new class of alloys where extreme chemical disorder plays an essential role. In a general N-component N solid solution alloy P A1c1 A2c2 . . . Aici . . . ANcN , ci ¼ 1 the chemical disorder, i¼1
as
measured
by N P
mixing DSmix ¼ kB
the
ideal
entropy
of
ci ln ci , is maximal at equiatomic
i¼1
composition, ci 5 1/N and increases with the number of components. In their ideal form, HEAs are exemplars of Address all correspondence to these authors. a) e-mail: [email protected] b) e-mail: [email protected] DOI: 10.1557/jmr.2018.300 J. Mater. Res., 2018
such maximally disordered alloys in that, by definition, they are comprised of N $ 5 com
Data Loading...
