Spin filter behaviour of atomic NiO chains in Ni nanocontacts

Contrary to the antiferromagnetic and insulating character of bulk NiO, we show by means of ab initio quantum transport calculations that short atomic NiO chains suspended between Ni nanocontacts can become strongly spin-polarized conductors. They could thus serve as nanoscopic spin filters. Here we study the stability of our results against geometrical distortions of the atomic chain and the nanocontact.