On magnetically dead layers at Nb–Co interface

Recent experiments indicate the presence of magnetically dead NbCo alloy layers at the Nb–Co interface. By using the tight-binding linear muffin-tin orbital method in the atomic-sphere approximation, we consider a number of one- and two-layer Nb–Co interfaces formed by disordered or ordered NbCo alloys. The interfaces separate fcc Co(111) crystal surface from a Nb monolayer. The presence of Nb atoms in Co neighborhood always leads to some reduction in magnetization. The crucial parameter controlling a Co-atom magnetization is the number of its nearest Nb neighbors. If this number is greater than about 5, the Co magnetic moment is essentially quenched, in agreement with experiment.