Weak ferromagnetism in Mn nanochains on the CuN surface
  We investigate electronic and magnetic structures of the Mn chains supported on the CuN surface using first-principle LSDA and LDA+U calculations. The isotropic exchange integrals and anisotropic Dzyaloshinskii-Moriya interactions between Mn atoms are calculated using Green function formalism. It is shown that the account of lattice relaxation and on-site Coulomb interaction are important for accurate description of magnetic properties of the investigated nanosystems. We predict a weak ferromagnetism phenomenon in the Mn antiferromagnetic nanochains on the CuN surface. The value of a net magnetic moment and direction of spin canting are calculated. We show that some experimental features may be explained using anisotropic exchange interactions. 
A.N. Rudenko, V.V. Mazurenko, V.I. Anisimov, A.I. Lichtenstein