The Cr-Doped Ni-YSZ(111) interface: Segregation, oxidation and the Ni equilibrium crystal shape

Abstract

In this work we studied the influence of Cr, as well as Fe combined with Cr, on the thermodynamics and structural characteristics of equilibrated interfaces between Ni and the (111) surface of yttrium stabilized ZrO2 (YSZ). Ni particles were doped with Cr, or with Fe and Cr. Chemical analysis of the interfaces was conducted using energy dispersive spectroscopy (EDS) in scanning transmission electron microscopy (STEM), and the equilibrium crystal shapes (ECS) were simulated using the “Wulffmaker” software. Cr was found to adsorb to the Ni-YSZ interface, and in parallel to create a Cr2O3 phase which partially wets the interface. The presence of Fe in solution in the Ni was found to reduce the amount of adsorption to the interface and prevent formation of Cr2O3. Furthermore, in both doped systems, the same orientation relationship as in the un-doped system was found, regardless of the significant change in the equilibrium crystal shape.