Structure, magnetism, and adhesion at Cr/Fe interfaces from density functional theory

Properties of the Cr(1 0 0)/Fe(1 0 0) and Cr(1 1 0)/Fe(1 1 0) interfaces are investigated with spin-polarized density functional theory within the generalized gradient approximation (DFT-GGA) for electron exchange and correlation. Contrary to earlier predictions for a monolayer of Cr on bulk Fe, we find intermixing of Cr and Fe at the interface of thick films to be endothermic; hence here we focus on characterizing abrupt, unalloyed interfaces. The ideal work of adhesion for both the (1 0 0) and (1 1 0) abrupt interfaces is predicted to be ∼5.4 J/m2. We propose that this anomalously strong adhesion between heterogeneous interfaces is derived from significant spin correlations and d-d bonding at the interface.