ABSTRACT
By means of first-principles computational experiments, the microscopic mechanism of metal-carbide adhesion is revealed. Density-functional-theory results for the Co /TiC(001) interface show the interface bonding to be dominated by Co-C bonds. The effective number of bonds is controlled by an interplay between lattice mismatch and relaxation effects. The particular strength of the Co-C bond is explained in terms of interface-induced features of the electronic states, in particular, a novel metal-modified covalent bond. The calculated adhesion strength agrees well with results of wetting experiments.
ABSTRACT
Atoms and molecules adsorbed on metals affect each other indirectly even over considerable distances. Via systematic density-functional calculations, we establish the nature and strength of such interactions, and explain for what adsorbate systems they critically affect important materials properties. This is verified in kinetic Monte Carlo simulations of epitaxial growth, which help rationalize a number of recent experimental reports on anomalously low diffusion prefactors.
