Effects of Co magnetism on Co/TiC(001) interface adhesion: a first-principles study

First-principles plane-wave pseudopotential calculations of the electron structure and energetics of the interfaces between the (0 0 1) surfaces of ferromagnetic fcc Co and TiC are reported. A detailed comparison with the case of the paramagnetic Co(0 0 1)/TiC(0 0 1) interface demonstrates that the Co magnetism lowers the adhesion work and increases the interface energy significantly, but practically does not affect the nature and strength of the interface Co-C bonds. The magnetic contribution to the interface energetics originates from the interface-induced changes in the magnetization energy of the interface Cc layer. This contribution can be adequately described within the Stoner model of itinerant ferromagnetism, taking the paramagnetic density of electronic states as an input. The found effects are expected to be important during the solid-state sintering stage of the hardmetal manufacturing process. (C) 2001 Elsevier Science B.V. All rights reserved.