Magnetism of 3d transition-metal monolayers on Cu(111) and Ag(111)

have studied the magnetism of 3d transition-metal monolayers (ML's) adsorbed on the Cu(lll) and AE(11 1) substrates by means of ab initio electronic structure calculations in several collinear magnetic orders. In comparison with the ML's on Cu(100) and Ag(100), we find many similarities but also interesting differences. The Ni ML's on Cu (111) and Ag(lll) are nonmagnetic in contrast to the Ni ML's on Cu(100) and Ag(100), which are ferromagnetic. The Co and Fe ML's on Cu(lll) and Ag(111) are ferromagnetic. The middle-of-the-series elements V, Cr, and Mn, usually present antiferromagnetic nearest-neighbor coupling, which is completely frustrated in a fee (111) ML (triangular lattice). Among the collinear spin structures considered here, we find the following ground states: V/Cu(111) nonmagnetic, V/Ag(111) ferrimagnetic with two up and one down spin in the root 3X root 3R30 degrees magnetic unit cell, Cr/Cu(111), Cr/Ag(111), and Mn/Cu(111) row-by-row antiferromagnetic, and Mn/Ag(111) two-rows-by-two-rows antiferromagnetic. We interpret the results in terms of localized spin models and discuss the possibility of more complex, in particular noncollinear magnetic orders. Comparison with inverse photoemission spectroscopy experiments for V and Mn ML's on Ag(111) yields reasonable agreement.