Enhanced Ni3Sn4 nucleation and suppression of metastable NiSn3 in the solid state interfacial reactions between Sn and cone-structured Ni

Abstract

Interfacial reactions of Ni micro cones with Sn at solid state temperatures from 373 K to 473 K were studied and compared with Sn/flat Ni diffusion couples. Due to its morphological characteristics, cone-structured Ni enhanced the nucleation of Ni₃Sn₄, resulting in thicker Ni₃Sn₄, which is also smaller in grain size and different in texture. At lower annealing temperatures (<423 K), cone-Ni also strongly suppresses the nucleation of metastable NiSn₃. The stripe-like micromorphology and special texture of Ni cones are believed to be the reasons for enhanced Ni₃Sn₄ nucleation.