Inter-element miscibility driven stabilization of ordered pseudo-binary alloy

An infinite number of crystal structures in a multicomponent alloy with a specific atomic ratio can be devised, although only thermodynamically-stable phases can be formed. Here, we experimentally show the first example of a layer-structured pseudo-binary alloy, theoretically called Z3-FePd₃. This Z3 structure is achieved by adding a small amount of In, which is immiscible with Fe but miscible with Pd and consists of an alternate L1₀ (CuAu-type)-PdFePd trilayer and Pd-In ordered alloy monolayer along the c axis. First-principles calculations strongly support that the specific inter-element miscibility of In atoms stabilizes the thermodynamically-unstable Z3-FePd₃ phase without significantly changing the original density of states of the Z3-FePd₃ phase. Our results demonstrate that the specific inter-element miscibility can switch stable structures and manipulate the material nature with a slight composition change.

Kenshi Matsumoto, Ryota Sato, Yasutomi Tatetsu, Ryo Takahata, Seiji Yamazoe, Miho Yamauchi, Yuji Inagaki, Yoichi Horibe, Masaki Kudo, Takaaki Toriyama, Mitsunari Auchi, Mitsutaka Haruta, Hiroki Kurata, Toshiharu Teranishi