Inter-Diffusion of Nickel and Palladium with Germanium

Abstract

Nickel and palladium germanides are the most promising candidates for nano-electronic contact materials to active areas of germanium-based devices. Solid-state reactions were thermally induced in conventional thin film couples of the Ni/Ge and Pd/Ge systems in order to study the sequence of phase formation. By embedding a thin layer of tantalum or tungsten as an inert marker between coupling thin film layers and observing its movement during phase formation, the dominant diffusing species were identified and monitored. In the Ni/Ge system, Ni 5 Ge 3 was the first phase to form followed by NiGe. The results showed that during Ni 5 Ge 3 formation, Ni was the sole diffusing species. During NiGe formation, both Ni and Ge diffused with the Ge diffusion prominent during the early stages, while the later stage of growth was dominated by Ni diffusion. The only phases observed to form in the Pd/Ge system were PdGe and Pd 2 Ge, the latter being the first. Palladium was the dominant diffusing species during both phase formations. Lateral diffusion couples were also prepared by the deposition of thick rectangular islands of germanium on to thin films of nickel and palladium. Several aspects of thermally induced lateral (as opposed to vertical) growth of phases were studied.

Mechanical and Microstructural Behavior of Sintered NiAl-Based High Entropy Alloy

“…However, in this investigation, the focus is on the NiAl. At low temperatures, NiAl is noted for its strength and brittleness, while at high temperatures, it has outstanding mechanical properties [7][8][9]. The addition of a phase refinement technique could be used to enhance NiAl's properties.…”

Optimization of process parameters for the development of Ni–Al-Ti-Mn-Co-Fe–Cr high entropy alloy system via spark plasma sintering

“…These intermetallic materials are alloyed to obtain more desirable properties. Most importantly, the nickel aluminides; γ' (Ni 3 Al: L1 2 ) and βʹ (NiAl: B2) are known for their strength and brittleness with excellent mechanical properties at an elevated temperature [7][8][9]. They also often exhibit excellent magnetic, superconducting, and chemical properties because of strong internal order and mixed (metallic and covalent/ionic) bonding [10].…”