Impurity effects on adhesion

We report a first-principles calculation of impurity effects on adhesion. C, O, B, and S impurities all cause a pronounced decrease in the adhesive energies of the Mo/${\mathrm{MoSi}}_2$(001) heterophase interface. S decreases the peak interfacial strength, while C, O, and B increase it. All impurities increase interfacial spacing in proportion to their covalent radii. Impurity mechanisms are identified.