Calculation of gas adsorption effect on magnetism of Co(0 0 0 1)

Extended calculations of C, N and O adsorption on magnetic Co(0 0 0 1) surface are performed within the local-density-functional tight-binding linear-muffin-tin-orbital atomic-sphere-approximation scheme. For the low-coverage p(2×2) overlayers, the Co magnetization is reduced by C and N roughly twice, the effect of O is weaker. For the dense p(1×1) structure the magnetization suppression by C or N becomes yet more marked and is large also for O. The sensitivity of results to details of geometry is moderate but not negligible. An exception is the O(1×1) overlayer showing a kind of the surface-magnetization instability. C, N, and sometimes O couple antiferromagnetically to the Co surface.