Agglomeration behavior of solid nickel on polycrystalline barium titanate

This letter describes the phenomenon that takes place between nickel/barium titanate couples when heated under conditions employed in multilayer ceramic capacitor manufacturing practice: a 4 h, 1300 °C isothermal anneal in 1% H2–99% N2. Dense, sputtered nickel films were observed to dewet the titanate and agglomerate into discrete or interconnected islands via a solid-state process. Up to a critical film thickness value of ∼ 1.4 μm, the degree of agglomeration was found to display an exponential dependence on the thickness of the original nickel film.