STRUCTURAL AND MAGNETIC-PROPERTIES OF ANNEALED [FE19NI81](12-ANGSTROM) AG-11-ANGSTROM MULTILAYERS STUDIED BY MOSSBAUER-SPECTROSCOPY, X-RAY-DIFFRACTION AND MAGNETIZATION MEASUREMENTS/

The influence of annealing on the properties of an ultrathin permalloy /silver multilayer is analysed using Mossbauer effect, x-ray diffracti on, magnetization and magnetoresistance experiments. A thick permalloy him is studied for comparison. From Mossbauer experiments, the existe nce of a 'magnetically dead' layer is ruled out. An interfacial zone c orresponding to about 1.2 monolayers is observed in the low hyperfine held range in the as-deposited film and disappears after annealing at T-a = 450 degrees C, when the layer structure is destroyed. The evolut ion of the hyperfine held is associated with both densification of the NiFe layers and interface improvement. From Mossbauer and magnetizati on measurements, the individual Ni and Fe magnetic moments have been e valuated. They exhibit different thermal dependences, in agreement wit h results on multilayers based on pure Fe or Ni layers.