Reduced compositional fluctuations in epitaxial NiAl thin films

Despite their favorable resistivity, cohesive energy, and adhesion properties, intermetallic compounds still face challenges related to compositional fluctuations. Here, we have studied this phenomenon in NiAl thin films utilizing atom-probe tomography and reciprocal space mapping. Our results demonstrate a substantial reduction of compositional non-uniformity in epitaxial NiAl layers. Structural characterization via reciprocal space mapping revealed a lattice parameter deviation of less than 0.5% from the bulk NiAl lattice constant, indicating a relaxed epitaxial structure. This strain-minimized epitaxial configuration can be understood as a primary mechanism for the reduction of compositional fluctuations in NiAl, highlighting the potential advantages of strain-relaxed epitaxial intermetallics for advanced interconnect applications