HALF METALLIC NIMNSB-BASED SPIN-VALVE STRUCTURES

Well-ordered NiMnSb single films were prepared by facing-target sputte ring down to thicknesses of the order of 10 hit. The magnetic and tran sport properties were similar to that of bulk poly-and single-crystals for which the half-metallic character is sustained up to 80 K. Spin-v alve structures were then realized using a Rile spacer layer and an am orphous SmCo2 biasing layer. A clear low-field spin-valve contribution of around 1% was observed at T = 60 K, superimposed to the bulk spin- disorder anisotropic magnetoresistance. Such a low magnetoresistance v alue, given the predicted full spin polarization, is mostly accounted for by the large Mo resistivity. Attempts to grow similar structures w ith Cu. Au or Ag spacer layers resulted in poor crystalline quality an d interdiffusion. (C) 1998 Elsevier Science B.V. All rights reserved.