Effect of hydrogen on the interlayer exchange coupling in Fe/V superlattices

Electronic and magnetic structures of Fe/V superlattices with and without h ydrogen in the vanadium spacer are investigated using a relativistic full-p otential linear muffin-tin orbital method. We obtained short-range induced spin polarization in V as well as reduced Fe polarization at the Fe/V inter face. The value of the magnetic moment induced on the vanadium atoms depend s strongly on the distortion caused by the lattice mismatch and hydrogen lo ading whereas the total moment of the Fe and V interface layers remains alm ost unchanged. Hydrogenation of the V spacer leads to the decrease of the i nterface magnetic moment on the V atoms and to a reduction of the density o f states (DOS) at the Fermi level. A low DOS could be one of the reasons fo r the experimental increase of the resistivity of the samples under hydroge n loading and leads to the disappearance of the antiferromagnetic exchange coupling in the Fe/(VH) superlattices for large hydrogen concentration. Dop ing the V film by a gold monolayer increases the DOS at the Fermi level and could recover the antiferromagnetic coupling.